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INSECT BEHAVIOR 



BADGER'S 
STUDIES IN SCIENCE 



The Highek Usefulness of Science. 
By William, Emerson Ritter. 

The Unity of the Organism, or The 
Organismal Conception of Life. Two 
volumes. Illustrated. By William Emer- 
son Ritter. 

The Beginnings of Science. By 
Edward J. Menge. 

The Probable Infinity of Nature 
and Life. By William Emerson Ritter. 

An Organismal Conception of Con- 
sciousness. By William Emerson Ritter. 

Insect Behaviok. Illustrated. By 
Paul G. Howes, 

Life and Death, Heredity and Evolu- 
tion IN Unicellular Organisms. Illus- 
trated. By H. S. Jennings. 

The Ornithology of Chester County, 
Pennsylvania. Illustrated. By Frank 
L. Burns. 

Familiar Studies of Wild Birds. Illus- 
trated. By F. N. Whitman. 

Questions and Outlines in General 
Chemistry. By W. S. Haldeman, 



RICHARD G. BADGER, PUBLISHER, BOSTON 




"They hover over the expanse below, occasionally swooping down upon creatures of lesser bulk' 
yEschnid dragon-fly feeding upon a house fly. Much enlarged 



INSECT BEHAVIOR 



BY 



PAUL GRISWOLD HOWES 



WITH ILLUSTRATIONS FROM 
PHOTOGRAPHS BY THE AUTHOR 




BOSTON 
RICHARD G. BADGER 

THE GORHAM PRESS 



{■■■■IHIHBMMI 



COPYEIGHT, I919, BY RiCHAED G. BaDGER 



All Rights Reserved 



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Made in the United States of America 



The Gorham Press, Boston, U. S. A. 



©CI.A559818 

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TO 

MY MOTHER 

WHOSE FAITH AND ENCOURAGEMENT 
HAVE PAVED THE WAY 

THIS BOOK IS FONDLY DEDICATED 



PREFACE 

IN preparing this little volume my object has been to produce 
a work written in a light enough vein to be entertaining to the 
reader, however casually interested he may be in insect life, but 
at the same time, one that is in every way scientifically accurate. 

In the chapters which follow, I have endeavored to describe as 
vividly as it lies within my power to do, various phases of insect 
behavior which I have been fortunate enough to observe and record 
during many years spent in active field work. 

Chapters II to VIII inclusive, treat exclusively of South American 
insects, studied in the jungles of British Guiana, and while they are 
interesting species, whose habits have heretofore remained un- 
recorded, they possess no more wonderful life stories than our insects 
of the Eastern States, whose habits, for the most part, make up the 
remainder of this book. 

Wherever one searches in the world of insects there is something 
new to be found. Perhaps only an unrecorded habit, or a slight 
problem to be solved, yet each problem leads to another, and soon one 
is led unconsciously into the depths of the study. Once in, there 
appears to be no way out, and I for one do not wish to retrace my 
steps to the freedom I knew before the fascination of this study laid 
hold of me. 

If this book leads others into the world of insect study or, in some 
measure, brings home to the reader, the same fascination that these 
life stories hold for the author, then its object will be fully realized. 

For the use of chapters II to VIII inclusive, which originally 
appeared in Volume I of Tropical Wild Life in British Guiana, I am 



lo PREFACE 

greatly indebted to the New York Zoological Society, and to those 

magazines who have published other chapters as separate articles, 

and have now given their consent to their use in this book, I wish 

also to acknowledge my grateful thanks. 

Last but not least, to Lillian Carey Howes, upon whom has fallen 

the main burden of preparing my manuscript for the printer, I make 

grateful acknowledgment. 

Paul Griswold Howes. 
Stamford, Conn., 

January i, 1918. 



CONTENTS 

CHAPTER PAGE 

I The Insect World at Close Range 19 

II The Black Reed-Wasp 27 

III Larval Sacrifice 33 

IV The White-Footed Wasp 40 

V Paralyzed Provender 46 

VI The Forest Shell-Wasp 53 

VII The One-Banded Dauber 60 

VIII The Blue Huntress 68 

IX Controlled Pupation . 77 

X Cannibal Wasps 85 

XI The Sphecid's Duty 91 

XII The Original Paper-Makers 95 

XIII Insect AND Other Strategists 102 

XIV Observations on Ants 109 

XV The Sight of Insects 125 

XVI How^ THE Greenbottle Does its Duty 129 

XVII Some Insect Experiments 134 

XVIII The Cecropia Moth 143 

XIX Nature's Way with Undesirables 147 

XX Spittle Bug Spittle . . . 151 

XXI The Life of the Thread-Legged Bug 154 

XXII Trailing a Bee to its Lair 160 

XXIII Camouflaged Insects 164 

XXIV Living Examples of the Geological Past .... 169 

Index 173 

II 



LIST OF ILLUSTRATIONS 

FACING PAGE 

iEschnid dragon-fly preying upon a house fly Frontisfiece 

A centipede greatly enlarged 21 

Grasshoppers fighting 21 

Staphylinid beetle preying upon a fly 22 

An assassin bug laying her eggs 24 

A handful of vegetation at close range 26 

A photograph made under asparagus plants 26 

Plough furrows are as mountain ranges to the insects 31 

A greatly enlarged hemipterous insect . 31 

Male black reed-wasp guarding nesting tube 33 

Female black reed-wasp arriving at the tube 33 

Glass tube removed from box, showing plugs, egg and spiders .... 33 

Old nest of wasp used by the black reed-wasp . 33 

Stages in the larval sacrifice 35 

Newly transformed pupa of the roach-killer 35 

Spider used as provender by the white-footed wasp 40 

Cocoon of white-footed wasp . 40 

Tangle of reeds and razor grass in British Guiana 40 

Two common bugs which do great damage to squash vines 49 

Open nest of the forest shell-wasp 56 

Open nest and larva of the forest shell-wasp 56 

Newly emerged one-banded dauber 65 

Suspended hatching egg of the forest shell-wasp 65 

One-banded dauber working upon her nest 65 

Four types of nests made by the one-banded dauber 65 

Spider prey and egg of the blue huntress 68 

Pupa of the blue huntress showing T-shaped jacks 68 

A queen paper wasp at her nest 72 

A cabbage butterfly depositing an egg folio-wing 76 

13 



14 LIST OF ILLUSTRATIONS 

FACING PAGE 

Cocoons of ichneumon parasite of cabbage butterfly larva 76 

Male and female paper-wasps hatching in July 81 

Paper-wasp worker with unusually large pellet of paper 81 

The cannibal's nest layed open 85 

A cannibal wasp at her nest 85 

The cannibal and her diggings 86 

A complete lead model of the cannibal wasp's burrow 86 

A wasp of the sphecid's size compared to a rove beetle 88 

Sphecid wasp dragging a paralyzed cicada to her burrow 88 

Common cicada, upon which the sphecid wasp preys 88 

Comparative wing expanse of cicada and sphecid wasp 90 

Hole in cicada through which the young sphecid entered 90 

Young sphecid wasp two days old feeding on its host 90 

Queen paper wasp in the act of depositing an egg following 92 

Photomicrograph of eggs of the paper wasp . following 92 . 

Paper wasp cells showing young and silken cocoon-caps 95 

Life size nest of paper-wasp 95 

Cells of the paper-wasp with caps removed to show young 97 

Paper wasp cells in section showing larva and pupa 99 

Epeira insularis, an orb-building spider, laying eggs I02 

A spider using a cicada's shell as a hiding place 104 

An example of spider strategy 104 

The fishing net of a hydropsychid and its maker ........ 106 

Ants surrounding and pillaging a larger one following 108 

Brown ants transporting aphids to their underground nest . . following 108 

Actual debris gathered up after an ant battle following 108 

Carpenter ants tending their aphid "cattle" following 108 

Paralyzed and dying South American leaf-cutter ants ill 

A group of dead ants all linked together lii 

Carpenter ants proceeding to battle 113 

A severed head of an enemy clinging to a dead ant 113 

A train of South American army ants 113 

Leaf-cutter ants with heads and abdomens eaten away 113 

Young brown ants carefully tended by their nurses 115 

Young brown ants brought up beneath a sun-warmed stone 115 



LIST OF ILLUSTRATIONS 15 

FACING PAGE 

A snowy tree cricket singing ii8 

The typical dragon-fly face 120 

A robber-fly with its prey 120 

Photomicrograph through the eye windows of a fly . . . . . . . . 122 

A harvestman following 124 

Egg mass of the greenbottle fly following 124 

A greenbottle laying eggs upon the head of a dead bird 127 

Greenbottle laying eggs in the bill of a starling 1 27 

Young greenbottle flies at work 129 

Skeleton of a muskrat cleaned by young greenbottle flies . 131 

Test tubes containing foods liquefied by young flies 131 

Nest of the mound-building ants 134 

Cecropia caterpillars twenty-five days old 138 

Cecropia caterpillar casting its skin 138 

Caterpillars of the cecropia just after the second cast 138 

Eggs of the cecropia on an apple leaf 138 

Female cecropia moth 143 

The full grown cecropia caterpillar 143 

Newly completed cocoon of the cecropia caterpillar 143 

Squash flower opened to show nectar cup 147 

How the honey bee reaches the nectar in a squash flower 147 

A beetle at the entrance of the nectar cup 147 

Fertilized blossoms of the squash plant 148 

The yellow gaping throat of a squash flower 148 

Foamy dwellings of immature spittle bugs 150 

Growth of the spittle mass 150 

A dried spittle mass and the mature insect 152 

Huge spittle mass found in the jungle of British Guiana 152 

A thread-legged bug laying eggs 154 

A stampede of thread-legged bugs 156 

Greatly enlarged head of the thread-legged bug following 156 

A characteristic attitude of the thread-legged bug following 156 

A thread-legged bug casting its skin 157 

Spring-tails in their tiny world 159 

Spring-tails showing spines upon their bodies 159 






i6 LIST OF ILLUSTRATIONS 

FACING PAGE 

A tiny solitary bee resting between journeys i6i 

Making a plaster cast of the bee's burrow i6i 

Entrance to the bee's tunnel showing surroundings i6i 

Model of the bee's nest made from a plaster cast 163 

Interior of the bee's burrow showing cell and food 163 

Excavating the cast of the burrow 163 

Caterpillar of a geometrid moth which resembles a twig . . . following 164 

Caterpillar which mimics the excretia of a bird following 164 

Chrysalis of the mourning cloak butterfly 168 

Cochlidiid caterpillar which mimics a leaf-bud 168 

Thread-legged bug in its original environment following 170 

Poison spines of the lo caterpillar following 170 

Wood lice or pill bugs 173 

A thysanuran or bristle-tail 173 



INSECT BEHAVIOR 



INSECT BEHAVIOR 

CHAPTER I 

THE INSECT WORLD AT CLOSE RANGE 

NOT SO long ago my world was commonplace; even dull at 
times. Tranquil and uninteresting, until one day a tiny 
voice broke the silence of my study. It led me from my 
dusty chimney corner, dropped me suddenly into the new 
and fevered world of insects, and there it left me. 

Who can tell how long this new world had lain before me un- 
noticed, a world of tiny people within our own big world, fighting 
out their destinies beneath our very feet? I found it a land of marvels 
and excitement, where great geographical upheavals are but momen- 
tary matters; where changes, rivaling those wrought by a million 
years in our environment, occur from day to day, a land where there 
is no uniformity of change. I found disorder and repose walking 
hand in hand, neither more of one than the other, yet much of both. 
I stopped; marveled, became fascinated, with this land so new and 
mysterious, into which I could step without effort, from my study 
door. 

There were jungles, immense ones, rank and tangled, grown with 
gigantic trees whose bark was an armor of thorns. Myriad life 
inhabited them, and a thousand different creatures prowled about 
hunting one another. In the tree tops, along their swaying trunks 
and in the tangles below, every living thing was fighting for exist- 
ence. Were our ears attuned to the vibrations of this jungle, a terri- 

19 



20 INSECT BEHAVIOR 

fying sound, dwarfing all others, would reach them, a grinding of 
life between myriad jaws, merciless, endless, for such is life in this 
new world. 

Such an existence in such a forest is'beyond our comprehension. It 
is the exception to survive long here. Each species preys upon, or 
fights to exterminate the next. There are serpents of great length 
and colossal rodents that comparatively dwarf a mastodon, which 
add to the excitement of life. It is fortunate that the creatures 
peopling such a world possess little if any intelligence. Indeed it is 
possible that they were purposely deprived of it lest they fear to 
venture forth. 

Now this jungle may flourish into a great wilderness, a forest 
whose real floor the sun never reaches. Here among the buts of the 
trees, weird creatures are encountered. Ugly crab-like things that 
suck the blood of others, minute horny creatures and indescribable 
crawling ones whose life story and functions nobody yet knows. 

Above the dead fallen stems that cover this tomb life, a second 
group of living things is encountered. Larger creatures capable of 
utterances of a harsh nature, hard shelled beasts and triangular- 
bodied ones that emit disgusting odors. 

One night the jungle flourishes, green and rich with swaying, surg- 
ing life and energy, but the next night it has vanished. Every tree 
has fallen by some mysterious hand; millions of creatures perish 
and all is confusion. What has occurred claims a greater toll than 
war, yet, as we shall see, it is by no means a miracle. 

Beyond the vanishing jungle lies a country of another type, the 
like of which no human being has ever seen. 

Imagine a series of parallel mountain ranges, three hundred in 
number, of great length, with as many narrow valleys lying between. 
The country is nearly barren yet strangely rich in soil. At great 
distances some green thing finds courage to lift its head, standing 




'Minute horny creatures and indescribable crawling ones whose hfe story and functions nobody yet knows' 

A centipede greatly enlarged 



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THE INSECT WORLD AT CLOSE RANGE 21 

out like a palm in an oasis, giving its mite of shelter from the sun. 
Lying about in no order, one sees great boulders, some rounded, others 
with jagged dangerous edges and many bearing white wounds as 
though a giant hammer had tried to cleave them. 

There is a scarcity of animal life here just as there is a scarcity of 
vegetation, but one or two creatures revealed by the hunt are inter- 
esting. 

One possesses a bony orange head that glistens like polished armor. 
It is armed additionally with heavy curved tusks, working sidewise 
with great strength, but for all this war-like apparatus its body 
is fat and pudgy. Such a hypocrite could be attacked from behind 
with safety. The creature rolls about aimlessly and one is forced 
to wonder how it obtains its food. 

Another is a hairy eight eyed creature, possessed of as many agile 
legs that carry it rapidly from place to place. It lives in damp caves 
beneath boulders, darting out upon the unwary. In the seclusion 
of its cave it sucks its victim's blood casting out the skeleton as a 
warning to others. 

We pass on. The journey brings us through another jungle of 
immense fruit trees bearing large objects resembling cocoanuts and 
thence to a lake of great extent, backed up by a group of mountains. 
Over the water one sees large flying creatures, with tremendous eyes 
and slender, plated bodies. They hover over the expanse below, 
occasionally swooping down upon creatures of lesser bulk, whom they 
consume greedily. 

In front of us there are slimy flats sloping toward the lake. Pufis 
of tainted air lead to the discovery of a mass of carrion near the 
water's edge. Here is something of interest. 

Upon the manna a multitude of animals are gorging. Most of 
them are similar in body, being long, fleshy and alert. They appear 
to be fighting greedily for the repast upon which they are exuding 



22 INSECT BEHAVIOR 

a strange fluid to assist digestion. They move continually about by 
means of grapnels which enable the animals to progress either for- 
ward or backward by repeated contractions of their muscles. 

Other animals are attracted by the odor of decay and from far 
and near they come to seek the cause. Some to their advantage, 
others to their detriment, for a cannibal lies in wait for them. 

It is a powerful animal, slender and supple-bodied, with a coat of 
glossy bronze velvet. It is perhaps the most active of all the weird 
creatures that we have come to know, moving like a flash in response 
to stimulae. It could not exist were patience a necessity, at least one 
is so impressed upon observing it. 

There are many tunnels twisting into the carrion, excavated by 
other creatures, and one of these the cannibal selects for its abode, 
until the flesh becomes too dry to act as lure. In this grewsome cave 
the creature rests, its eyes roving and its whole body ready to spring at 
an instant's notice, which it does upon all who venture within its 
range. Indeed we have found a veritable dragon in this creature 
so fiery and ready for battle. Its prey is helpless before the on- 
slaught and its teeth sink easily through armor. 

Leaping upon the back of its victim, the dragon tears deep into 
its body, grinding flesh and skeleton, sucking every drop of blood 
until the broken creature curls, dry like a leaf. In a few seconds 
the unlucky one has disappeared before our eyes. A minute ago 
we saw a living creature come to the carrion to stay its appetite. 
Next we heard a crunching noise and saw a splash of blood. Now 
there is nothing but the retreating cannibal and we gaze dumb- 
founded at the spot where the scene was enacted. 

From the lake we journey on, through a wide and heavy section 
of woodland, on our way to the desert that lies beyond. As we go 
we have many weird experiences and see many curious sights, but 
lack of time prevents their proper observation. We must reach the 




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THE INSECT WORLD AT CLOSE RANGE 23 

desert at once, lest we arrive too late to see the pitfalls of the desert 
lions. 

At length the broiling sands are reached and none too soon. The 
lions only build their traps at certain times of the year and few signs 
of them are encountered. A search reveals four pits, however, placed 
in the neighborhood of a colony of burrowing creatures common to 
the desert. 

The pits are deep conical excavations in the sand, so cunningly 
constructed as to compel admiration despite the clumsy makers, 
who walk backwards in preference to forward. 

At this time the lions are still youthful and being grotesque and 
cumbersome of body, must therefore secure their prey by strategy. 
Each individual excavates a pitfall, cone-shaped as we have seen. 
At the apex of the cone, which is deep in the ground, the creature 
conceals itself with only the sabre-like, sand-colored mandibles 
protruding. 

Let us watch from a safe distance the methods employed. We 
have not long to wait, for a constant stream of animals are pouring 
in and out of their burrows near by. Many keep at a safe distance; 
others escape more through good fortune than intelligence, but at 
length a stupid individual arrives at a pit and heedlessly places one 
foot over the edge. 

At once the footing crumbles and the poor animal starts on its 
journey. Once, in its frantic struggles, it appears to regain the lost 
footing, but seeing or expecting this, the lion hurls a multitude of 
rocks from below, which once more start the sand sliding and the 
victim meets its death in merciless, waiting jaws. 

Now we might travel on and on, from the desert to another valley, 
lying between inspiring mountain chains, thence to a dried up ocean 
bed, across a great river into more jungle and so on, indefinitely, wit- 



24 INSECT BEHAVIOR 

nessing an endless series of geographical and living wonders that 
would soon bewilder us. 

We can go no further now. Our expedition into the new world 
must needs come to an end. Before we return home, we are, how- 
ever, to witness the approach and arrival of a new period. We are to 
see with our own eyes and in a very short time, the temporary death 
of this curious land. 

The period, which is a glacial one, comes rapidly and is marked 
by great frosts, capable of killing an entire jungle in a single night. 
With each successive frost, countless millions of creatures perish, 
the weakest dying at once, the stronger surviving for a slightly longer 
period. Lakes and oceans freeze solid from surface to their depths, 
valleys and mountains are buried with snow and in an incredibly 
short time, perhaps a month or two, life in this lately flourishing land 
through which we have traveled may be cold and dead. 

A glacial period has come, transforming the land into a desolate 
waste. It has apparently carried all life before it. 

A fertile earth today, a barren moon tomorrow, such is this new 
world within our own! 

******* 

Let us now see just what this new world is and where our travels 
have led us. We have barely looked into its treasure house of won- 
ders, but for all that, we have learned something and our eyes have 
been opened to its possibilities. 

Its geography is our own, more minutely seen, analyzed as it were 
into its smallest parts. To study its wonders one must lose sight 
of all large unimportant things. Real mountains, lakes, deserts, 
objects that make our geography, all must be ignored. They are 
too evident to be considered and to bother with them as a whole 
would be like hoarding something without value. 

If we examine a great painting closely, we see only a melee of mean- 




AnotluM' stiMiiiii- cioatun- of the insect world 

An assassin Inii; layiiiji lur cgus 

I'.nlarjicd six tiniis 



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THE INSECT WORLD AT CLOSE RANGE 25 

ingless strokes; dabs of color placed together like the patches of a 
crazy quilt. So we may liken this new, or insect world, to these 
strokes and dabs that collectively make the painting. In a word the 
new world consists of the particles that, heaped together, compose the 
mountain, the valley and the desert of our own. 

When we were coaxed from our study by the excitement of dis- 
covery, we stepped across the lawn into a field of waving hay. It 
was bordered with a heavy growth of weeds and other vegetation. 
Stopping to analyze, we found a jungle of the insect world. At the 
other end of the field the farmers were already swinging their 
scythes — thus the jungle vanished in a day. 

We journeyed on to another field, so recently turned over by the 
plough that vegetation had only appeared at intervals. There were 
three hundred furrows, mountain ranges to an insect. There were 
stones bearing plough wounds, a few drassid spiders under them and 
here and there a fat white grub rolling helplessly about. 

Next we passed through a patch of asparagus with its rounded fruit. 
Beyond this a clear little puddle was sighted over which dragon 
flies hovered, occasionally swooping down upon smaller insects. The 
far bank of the puddle was composed of sand and stones heaped to- 
gether like conglomerate, but in front was a muddy flat upon which 
some frightened creature had dropped its animal prey. 

In the flesh of this unfortunate we found a swarm of maggots, 
young flies whose duty it is to liquefy such objects and return death to 
life. Beneath the carrion a rove beetle lay in wait for unwary mother 
flies who came to lay their eggs in the game. 

Leaving the pond for pastures new, we crossed a sandy field. Here 
several ant lions had made their pitfalls to entrap blundering ants, in 
whose formic acid they find nourishment and a pleasing flavor. 

And so we might travel on and on, endlessly were it not for winter. 
Frosts are messengers of death in the insect world. Each drop of 



26 INSECT BEHAVIOR 

the mercury reduces its myriad life until at length there is nothing 
left. We witness the coming of the frosts, then the snows, exter- 
minating all the little people that we have learned to know, for with 
winter comes the temporary death of their world. A queer little 
world that may be a fertile earth today and a barren moon tomorrow. 




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CHAPTER II 

THE BLACK REED-WASP 

Trypoxylon cinereohirtum, Cam 

WHERE man has felled the primitive forest, obliterat- 
ing nature's labors of half a thousand years, he leaves 
a wound that is long in healing. Just as a wound in 
the flesh leaves a scar that stands out distinct from its 
surroundings, so the forest heals its injury with a new vegetation, 
distinct from itself, but a mask nevertheless to the ghastly wound 
lying beneath. 

We call the mask second growth. It is made up of trumpet trees, 
weakly shoots from fallen forest giants, great waves of razor-grass, 
briars, various types of undergrowth and here and there a patch of 
canes whose hollow stems are the natural nesting sites of the black 
reed-wasps. 

Abandoning their natural habitat for the advantages afforded by 
Kalacoon,^ they flocked to our hospitable board, setting up their 
abodes in our pen-holders, in spools, nail holes, in the handle of my 
shaving glass, and, in fact, in anything that suggested a hollow tube 
with a tiny diameter. 

To the general rule among Hymenoptera ^ the black reed-wasps 
are an exception. That is to say, they are neither social, in the usual 
community sense of the word, nor are they solitary. They came in 
mated pairs in search of nesting sites, inspecting all the best holes 

^ A laboratory in the jungles of British Guiana where the author encountered the 
subject of this chapter. 

^ An order of insects including ants, bees, wasps, etc. 

27 



28 INSECT BEHAVIOR 

in the house with great care and deliberation. Like so many newly 
married couples, filled with the enthusiasm of a novel project, they 
roamed about among the improved property that Kalacoon offered. 
To facilitate my studies of their life history, I placed several pieces 
of glass tubing, three or four inches long and a quarter of an inch 
in diameter, about the laboratory. I inserted the tubes, which were 
closed at one end, into pasteboard boxes, leaving the open end of 
each projecting, so that the entrances were in plain view, but the 
main part of the passages were quite dark, within the boxes. Thus I 
made conditions in the tubes exactly like those in the reeds that the 
insects naturally chose for their nests. 

They were an instant success, and within an hour or two, all were 
occupied by enthusiastic couples. In the glass nests, I could watch 
everything that went on. All that was necessary for me to do in 
order to observe the occupants' behavior, was to remove the box 
covers, and replace them when I had finished. 

True to the tradition of wasp history, the female proceeds with 
the hard labor of nest building and providing for her family. The 
male, while he never actually takes part in the work, sits menacingly 
in the entrance, during his mate's absence, guarding the nest from 
intruders of the same species that are ever-ready unbidden to acquire 
a partly prepared home. He shows great interest in the work, fol- 
lowing the female into the tunnel, watching closely whatever she may 
be doing and squeaking continually in a high pitched key by vibrating 
his wings. This is a common habit among many wasps during work 
hours, but the species in question emits this strange little rasping 
sound during almost all of its occupations. I interpret it as an 
expression of pleasure or well-being, like a man who whistles at his 
job. The sound is never heard during fright or anger, but of this 
I shall treat in another chapter. 

Upon occupying a tube, the female's first procedure is to place 



THE BLACK REED-WASP 29 

a plug of solid mortar in the end of it, doubtless to prevent parasites 
and ants from entering. This plug is two millimeters in thickness 
and composed of wet, light gray clay. It dries in a few hours, harden- 
ing into a tough cement. Next to this, a second plug, one millimeter 
in thickness, is placed, containing more moisture than the first and 
of a much darker shade. This is followed by a third one of the 
same description, placed five or six millimeters in front of the second 
plug, so that there is an air space between them which holds moisture 
in the nest. The tube is now provisioned with small spiders of dif- 
ferent species, varying from five to eight in number, which are 
paralyzed by the wasp's sting and brought in one by one. They are 
packed tightly into the tube by the insect's broad head which is 
brought into use as a sort of ramrod. The tube is a tiny muzzle- 
loader, into which she packs her living wads without mercy. 

Upon the side or apex of the last, and usually the largest, spider's 
abdomen, she deposits a milky-white, bow-shaped egg, two milli- 
meters in length. It is less than one-quarter as wide as long and 
closely resembles a sausage. The spiders and the egg are now en- 
closed in a substantial cell averaging twenty millimeters in length, by 
the insertion of a double plug of mortar, six millimeters in thickness, 
half of damp, dark-colored clay and half of the hard lighter material. 
The nest is now abandoned by the parent wasps who often start imme- 
diately to provision a second one. 

In two days the egg hatches, bringing to light a yellow-white grub 
of thirteen segments. It commences feeding at once upon the 
spiders, a process which may be observed under the lens as a series 
of ripples or waves, commencing just behind the head and continuing 
the entire length of the body, — one wave being completed or spent, 
before the following one sets in. It grows rapidly, but very steadily, 
increasing each day in the same ratio until the last twenty-four hours 
of feeding, when it gains somewhat less than during the previous days. 



30 INSECT BEHAVIOR 

In all, the larva or grub is full grown in four days from the time it 
hatches. 

Upon finishing its meal, which lasts continuously for four days, the 
larva spins a flimsy net work of silken threads inside of which the 
cocoon proper is spun. This inner cocoon resembles a tiny torpedo, 
rounded at both ends and ten millimeters in length. It is very neatly 
constructed of delicate silk and coated all over the interior with a 
brown varnish that hardens in contact with the air. 

Within this delicate cradle, ten days later, the budding wasp under- 
goes pupation — that wonderful process described more fully in the 
following chapter — by which the footless grub is transformed from a 
low and ancient form, to the highest order of modern insects. The 
actual change from gorged grub to a neatly folded, but colorless wasp 
is affected in ten days, but it still has three hundred and twenty-eight 
hours of confinement separating it from the light of day, hours which 
must be passed quietly, lest injury result. 

As the hours go by, color at length flows through its body and 
appendages, transforming opaque yellow to glistening black. Then 
comes the final gift of nature, the power of motion. The nascent 
creature, moist with birth, bursts its cocoon, gnaws through the plug 
" of mortar and issues into the outer world a perfect insect. Only 
thirty-eight days have passed since I placed the tubes in the 
laboratory, and since the parents of this new creature arrived, real- 
izing their destiny. 

There is an interesting problem to solve concerning the black reed- 
wasps. Their nests vary considerably in number of cells. Some 
are complete with one, others contain two, but the majority are com- 
plete only after an egg has been laid upon the stores in three separate 
compartments. The question arises, How will the wasps emerge 
as perfect insects without disturbing one another? 

If the nest is to shelter three insects, the cell farthest from the 




Plough furrows are as mountain ranges to the insects 




'Above the dead, fallen stems that cover this tomb-life, a second group of livmg things is encountered' 

A greatly enlarged hemipterous insect 



THE BLACK REED-WASP 31 

entrance will naturally receive the first provisions collected, and, it 
would seem, in due time, the first egg deposited. The remaining 
two cells would receive their respective contents in the order of their 
position, but the first egg laid, naturally hatches before the others. 
The grub reaches maturity, pupates and is ready to emerge some- 
time ahead of its sisters in the other cells. What happens then? Does 
the issuing wasp burrow its way out through the cells in front, up- 
setting in its passage the vital conditions of solitude that surround the 
younger insects? Does it burrow through the clay plugs, separating 
each nursery, and as a final act of vandalism, leave the nest open, 
exposing its younger sisters to the first parasite? 

So it would seem, but such a course would be contrary to all the 
laws of nature. She does not destroy her children needlessly, yet I 
wonder what happens in such nests as that of the black reed-wasp, 
whose oldest child seems farthest from the door to freedom! 

Perhaps the parent wasp is gifted with the power of laying eggs 
that require varied terms of incubation. In the first cell provisioned 
she lays an egg that requires three days to hatch, in the middle cell 
one that requires two days and in the outer cell the egg hatches in a 
day and a half. The theory would straighten out the dilBculty 
very nicely. The insects would emerge in turn without disturbing 
one another and all would be well, but a theory is no better than a 
guess. Moreover a little careful observation of the glass tubes yields 
the correct and simple answer to the question. 

I watch a wasp entering one of the tubes carrying a spider which 
is held tightly beneath her body. She enters, stores the game, 
squeaks about it to her watching mate, and is off again in search of 
a second victim. She does not rest after placing eight spiders in the 
tube, yet this is the maximum number for a single cell. Instead, 
the work continues during most of the day without interruption. 

In the afternoon I open the box containing her nest. The tube 



32 INSECT BEHAVIOR 

contains twenty spiders separated into three little groups by half 
partitions of clay. Upon the abdomen of a large spider in each 
group she has deposited an egg. Now I close the box and await her 
return. She arrives laden with a tiny ball of clay in her mandibles, 
enters the nest for a moment and then flies off minus her burden. 

At the end of an hour the operation has been repeated twenty 
times. Now she commences to close the entrance with the same 
material. The job requires ten more loads of mortar, but it is 
completed rapidly. By evening she has left the nest, I presume 
for good and all, and for the last time I pry into her secrets. 

It is all very clear. In a single day she has accumulated the 
entire amount of provisions necessary to provide her three off- 
spring, and separated them into distinct groups. Further she has 
constructed half partitions that keep the stores separate, but still 
permit her to pass from one end of the nest to the other. Thus she is 
enabled to deposit her three eggs in different departments of the 
nest, all on the same day. The laying over, she has only to finish 
the half partitions with a few loads of clay, plug the entrance and 
her work is completed. 

She deposited all her eggs within an hour and they are safe in 
isolated cells. The three will pass through their metamorphosis or 
life history, as one. They will eat and grow and pupate together, 
and issue into the world almost at the same moment. Thus the black 
reed-wasp solves the problem very simply. She brings her offspring 
into the world as triplets! 



J 




-"wssr7^»»T^^ " 


\ 




Male black reed-wasp guarding 
nesting tube 



Female black reed-wasp arriv- 
ing at the tube 



Glass tube removed from box, 

showing plugs, egg, and 

spiders 




An old nest of a jungle mud-wasp, the empty cells of which were used as nurseries by the black reed-wasp 



CHAPTER III 

LARVAL SACRIFICE 

IT is Strange what a vast array of facts are disclosed through the 
study of the unintelligent invertebrate. I am thinking particu- 
larly of insects, dominant creatures of the earth, into whose life- 
secrets and lore man, through his wretched span of years, may 
scarce become a trespasser. They are set apart, almost in another 
world, vastly wise and ruled by an iron discipline that has wrought 
their world empire of today. My attitude toward the insect is that 
of a pupil under a great master, who, unable ever to reach the altitude 
of his mind, must be content to set forth his simplest teachings. No 
matter where I look, my master is there, a superior being who appears 
to have risen far above me. From his instinctive throne, he looks 
down pityingly upon my intelligence, I who must put two and two 
together and work my poor brain so hard to understand his simplest 
problem. 

Words fail to tell adequately of what I see in the world of insects. 
Then again there is much that I fail to understand anyway, as a 
consolation for the missing words, but occasionally I have just a faint 
glimmer of what is transpiring before my eyes. Thus I shall skip 
briefly over the life history of a wasp I call the roach-killer. Podium 
rufipes (Fabr.), to the subject of this chapter. 

The roach-killer is a solitary mason wasp, who has taken advantage 
of man's intrusion into her domain. His houses and buildings afford 
safer quarters for her nest, which originally she cemented to the con- 
cave sides of stumps or forest trees. Now she has partly abandoned 
the old sites for the immovable wooden shutters of tropical civiliza- 

33 



34 INSECT BEHAVIOR 

tion, where her rough red columns of clay stand for years as monu- 
ments over the birth beds of her of]fspring. 

The nest, a single column of clay, two and one-half to four inches 
in length and close to three-quarters of an inch in diameter, consists 
of a series of V-shaped layers placed side by side. The entrance 
to the nursery faces toward the ground. Inside it is divided into 
several ten by twenty millimeter cells, never exceeding four in num- 
ber, which, compared with the exterior, are quite smooth and pol- 
ished. 

Here is an interesting fact; if the wasp has chosen her original 
habitat among the stumps, she abandons it when finished as an incon- 
spicuous gray blotch that blends nicely with its surroundings. In the 
forest she finds no red or orange clay for building material. The 
swamps yield a rich brown and the brook banks a shade of gray. 
The nest is of necessity somber in color. On the other hand, the 
nests placed in the shutters of houses were all of rich, orange-red 
clay, collected from a nearby excavation in the trail. They were 
conspicuous objects to say the least, but the wasp quickly covered her 
fresh paint with a neatly arranged layer of termite's wings, cast ofT 
spider's skins and other bits of refuse. At first I put the occurrence 
down as accidental, but careful examination leads me to believe that 
it is a regular habit of the wasp, in view of the fact that not a square 
millimeter of the underlying clay showed through the veil. When 
the nests were finished they appeared old and disused. 

Each cell is usually provisioned with four wood roaches. Upon 
the last one placed in the cell a single white egg, with a yellow 
median line, is deposited. It is thrust under the fore leg of the 
roach, where the leg joins the insect's body. It is a tender spot where 
the young wasp, two days later, may easily bury its head in the 
creature's flesh. The number of roaches in a cell varies according 
to their aggregate. Thus a cell may contain two medium and one 



J 




Stages in the larval sacrifice, showing gradual changes from larva to pupa. (Life size) 




Pupa of the roach-killer just after transformation from the larva. Greatly 

enlarged 



LARVAL SACRIFICE 35 

very large insect, or six small ones, and while there is variation 
in the number of victims, the total bulk and food value of each cell's 
contents remain the same. 

Two days after the egg is deposited and the cell sealed up with 
clay, the young roach-killer hatches. It is but a tiny grub of thirteen 
segments, two millimeters in length, rather transparent and concerned 
only with its mouth and digestive tract. For two days it gorges, 
selecting only the tenderest, juiciest parts of its victims, leaving the 
legs and other less nutritious parts untouched. On the fifth day of 
its existence, it returns to these left-overs, going over and over them 
until all nourishment is gone. 

One hears the glutton plainly at its feast. Sip-sip-sip, comes 
the rhythmic sound. Its entire body throbs in unison as the greedy 
creature dives deeper and deeper into the grab-bag of the roach's 
anatomy. In five days the feast is over. The wings, egg cases, shells 
of the heads and thorax, together with the hard limb skeletons of the 
roaches are left uneaten in the end. They lie about the cell in fine 
disorder as lasting evidence of the grub's revelry. 

Immediately upon finishing the repast, the larva constructs a net- 
work of silken threads, just enough to prevent its rolling about. 
Within this cradle, an inner cocoon is formed, composed of threads 
much more densely spun, and finally coated within, with a reddish 
brown fluid that hardens in contact with the air, into a brittle skin. 
The process of spinning and coating requires eighteen hours for com- 
pletion, after which the larva excretes the waste from its five-day 
gorge in a single mass at one end of the cocoon. 

Spinning over, there comes a ten-day pause in the creature's activ- 
ity, during which time we shall witness the Larval Sacrifice. This 
process, known as pupation, is in many respects the strangest and 
most wonderful of all physiological transformations that take place 
in the insect world. We will see the grub, which in reality is but 



36 INSECT BEHAVIOR 

the ancestral form of the wasp, transformed by what we might call 
a "second birth," from its lowly worm-like body into an utterly 
different and highly specialized member of the topmost order of 
modern insects. 

We have traced the larva from the time the parent wasp deposited 
it as a tiny tgg upon the roach's body. We have watched its growth 
from day to day and observed how it tackles one victim, consumes 
it, searches out a second, then a third and fourth: how it eats the 
tender portions first and returns later to coarser fare. Its actions are 
almost those of a creature conscious of its life and appetite, which 
thinks only of its stomach and so many good things to be consumed. 
But the minute the repast is over, and the cocoon spun, we see this 
energetic and ravenous bit of life cease all outward activities. 

From young to full-grown larva, the creature is, in a measure, 
master of itself. It moves about in the cell of its own accord, feeds 
itself copiously and rests if need be, but thereafter it must surrender 
to an incomprehensible power, an invisible surgeon who will anes- 
thetize the grub, tear down its old body and bring forth a new and 
better creature from the havoc of his scalpel. 

During the operation, many of the larval organs and tissues are 
entirely done away with, and at the same time many parts of the new 
insect are derived from them. There is no spilling of blood, no 
suffering, no consciousness of what is taking place within the larval 
skin. From the exterior we sec nothing to hint of what is transpiring. 
All is serene during the ten days that the operation requires for com- 
pletion. 

This strange process of "second birth" (I have no adequate term 
for it), is unknown in creatures other than insects. From the blood 
and tissues of the horse, the foetus is produced, and eventually born. 
It arrives quite like the parent except for minor details. Without 
radical changes it feeds, lives and grows to maturity. In the 



LARVAL SACRIFICE 37 

chicken we have the egg, then the young, different at birth from the 
parent, but rapidly growing to resemble it, upon the addition of 
food to the youngster's stomach. In the wasp we have an egg, 
followed by a grub that is unable, simply by eating, to become like 
its parent. Something more radical is necessary, a complicated bit 
of surgery which will knock down the larval house and raise an imago 
from the ruins ! 

Thus in ten days after the larva spins its cocoon we see a slight 
shrinking of the body. A depression just off center follows. There 
is a tremor, ever so slight, then slowly the whole perfect insect un- 
folds from the grub like a nascent flower from its bud. It may re- 
quire a million years for processes of evolution to become established 
into a train of events, yet here in the course of a few days, by watch- 
ing this wonderful transformation from grub to pupa, we have 
actually witnessed the ancestral form sacrificing itself to a modern 
one! 

The processes that bring about such radical changes in the insect 
are known as histolysis and histogenesis. The former covers the 
breaking down and disintegration of the larval tissues and the latter 
the building of the new body, in part independent of the old material. 
There is little known of these strange performances, yet it appears 
to be the general belief that for the most part the perfect insect is 
developed chiefly from the skin cells of the larva. Therefore, I shall 
set forth what I have been able to gather through the logic of observa- 
tion, about this point. I make my statements guardedly — simply as 
facts that appear to have been overlooked. 

A yacht is built and launched. She serves admirably as a pleasure 
craft and is quite satisfactory for that purpose. War is declared. 
She is commandeered by the government for patrol duty and must 
be altered to meet new requirements. She is dry-docked, fitted with 
guns, more powerful engines are installed, and lastly she is painted 



38 INSECT BEHAVIOR 

the battle color. Later the craft appears once more upon the water. 
Altered tremendously, the old hulk still serves the fundamental pur- 
pose. It is much the same with the insect. The larval wasp is 
commandeered by nature. She must be fitted to meet new conditions 
in order to perpetuate her race. Thus the task devolves upon his- 
tolysis, the wrecker, and histogenesis, the builder. 

During the period of larval growth, from the time it hatches 
until the provisions in the cell are entirely consumed, the grub rids 
itself of no waste matter whatever. Unlike the larva of the butterfly 
that excretes every few minutes as it eats during the days of its worm 
life, the young wasp waits until its stores are gone and its cocoon 
spun before passing off the waste of its five-day gorge. Even then it 
waits another day before finally depositing it in a single mass at the 
lower pole of the cocoon. A few days later pupation takes place. 

In the days which pass, between excretion and pupation, no foreign 
matter appears within the cocoon. The insect is motionless: its 
cradle, save for the hardened mass at one end, is scrupulously clean. 
I remove this mass, float it out in a little water and subject it to a 
thorough inspection under the microscope. It contains bits of chitin, 
hairs and fragments of claws, all, however, fragments of the deceased 
roaches. There is nothing unusual in the array, no bits of larval 
anatomy, no fragments of the grub itself. What then becomes of the 
material that histolysis is supposed to dispoil? Are the skin cells all 
of the grub's anatomy that serve to build the wasp? 

I cut open the body of a grub, three days after the cocoon is spun. 
The greater part of it runs through the incision as a smooth, pasty 
liquid, amorphous in every way. At eight days, I open a second 
grub. Now it is partly paste, but mostly wasp ! 

The laborers of histolysis are not altogether wreckers then. They 
are concerned more with tearing down the old timbers, removing the 
rusty nails, puttying the holes and handing them back to the equally 



LARVAL SACRIFICE 39 

skillful employees of histogenesis, who in turn rebuild the house 
along more modern lines. 

Twenty-four days after pupation the insect issues from the cocoon, 
drills a neat hole through the wall of its nursery and emerges into 
the sunlight a perfect insect. Behind her, she leaves a few, very tiny 
pellets of white excreta. These are the rusty nails from the old 
structure. They are all I can find of the larval body that is not 
incorporated in the new. 

Fruit from the tree of instinctive wasp-love, the newborn insect 
is only an atom in the world, but what a bundle of unsolved mysteries 
to the humble student of her secrets! At her "second birth," she 
becomes her own mother ! Not content with skin cells alone as build- 
ing material, histolysis and histogenesis have rebuilt the Huntress 
from herself. She flies into the world with a freslv coat of paint, 
remodeled, a thing brought up to date, but somewhere underneath, 
lie the old timbers, reshaped and sawn to meet the new plan I 



CHAPTER IV 

THE WHITE-FOOTED WASP 

Trypoxylon leucotrichium, Rohmer 

AN alert business-like insect, deep steel blue with a white 
band encircling each of her hind tarsi, the white-footed 
wasp is readily recognized. She inhabits the hot open 
trails where bamboo grass has been slashed in clearing, 
leaving here and there a severed hollow stem hanging in mid-air and 
supported by the plant's shriveled leaves, which catch among other 
foliage. These hollow tubes supply the insect's favorite nesting sites, 
unapproachable from below except by winged enemies. 

The reed which the wasp had chosen had been severed by a knife 
slash so that its end was sliced off at a gentle angle. It hung four 
feet above the ground in a heavy patch of bamboo grass with its 
open end pointing toward the earth. Several other open reeds of 
the same character surrounded it, appearing to me very much the 
same. Not so to the wasp, however, she differentiated at once, and 
upon returning from her journeys, flew directly to the reed of her 
choice. There was no uncertainty in her approach, no repeated 
trials to find the proper entrance. A straight, single flight from the 
outer world to her tube marked her arrival. What a contrast to the 
clumsy one-banded dauber who wastes her precious time! 

I first found the white-footed wasp gathering a ball of soggy clay 
in a pitfall trap in the trail leading to the forest. Several of these 
holes had been excavated and for their intended purpose of catching 

frogs, toads and the smaller rodents they were perhaps less produc- 

40 




Species of spider used as provender by the 
white-footed wasp. 




Nesting reed of white-footed wasp opened to show 
elaborate cocoon. 




1 angle ot reeds and razor grass in Hritish (uiiana. In the ends of tiuse reeds, wiien cut or broken, the white- 
tooted w.isp nuikes hir nest. 



THE WHITE-FOOTED WASP 41 

tive than they were of wasps. The pits, after a rainfall, often con- 
tained several inches of water. When bailed out, a pasty layer of clay 
would be left in the bottom of each. This material, a ready made 
mortar, proved attractive to a number of wasps, which used mud 
in the construction of their nests. Tiny little reed-wasps, medium- 
sized ones, big blue huntresses, daubers and a dozen others collected 
at this abundant public property. Here, side by side, they gathered 
their building material, all laboring in a great common design for 
the welfare of their race in the future. 

The wasp brought several loads to her tube, scraping it up from 
the floor of the pitfall and carrying in it little globules to her door- 
way. Once within, a high-keyed squeaking and buzzing would con- 
tinue until the clay was thoroughly kneaded into a safety plug 
at the upper end of the reed. Her trips between nest and pit were 
continued for nearly an hour, like a hod-carrier laboriously plying 
between mortar box and masonry. After many trips back and forth 
she disappeared, returning in a little less than half and hour with 
a limp, paralyzed spider. 

The victim, a medium-sized creature, was richly colored and 
patterned in various shades of brown. Its body was quite small, 
measuring six millimeters in width, but the legs, all of which were 
intact, were long and rather cumbersome to the wasp. With her 
burden she flew directly to the entrance of her nest. She alighted 
with difficulty, then turning about and grasping the spider by one 
of its palpi she endeavored to enter the reed backwards. All went 
well for a time. The victim's cephalothorax and fore legs caused 
no trouble, but its abdomen caught at once upon the sharp edge of 
the reed, which tapered almost to a point. From this point the 
spider would not budge — and what is more, was in great danger 
of being punctured. Had the wasp pulled too hard it certainly 
would have been impaled on the reed and ruined for future use. 



42 INSECT BEHAVIOR 

Here I witnessed a most skillful performance. Clinging to the in- 
terior of the reed with only her two posterior claws, the wasp lowered 
the spider very carefully and deliberately until its entire body 
swung free in the air. Here, clasped tightly in the wasp's strong 
mandibles, it was held by its two front legs, and rotated, so that its 
abdomen came into the position so lately held by the cephalothorax. 
Then walking backward up the tube the wasp succeeded in bearing 
her victim to its last resting place. 

As I have already stated, the wasp seeks out spiders which, al- 
though of moderate size, possess long, slender legs, and there is a sim- 
ple significance in her choice. The wasp's nest is a hollow reed whose 
smooth perpendicular walls end abruptly in space. Her front door 
gapes in the void and must be approached from below. The spider's 
body alone is considerably smaller than the diameter of the tube. 
Thus were the wasp to choose a short-legged victim it would drop 
from the nest at the instant of release. The long legs of her spider 
are doubtless burdensome, yet they are a necessity to the success of 
her work. In drawing them into the reed, their legs fold back be- 
tween abdomen and reed, filling the intervening space so nicely that 
the entire creature remains wherever the wasp places it. 

Four of these spiders are allotted to each of the three cells, which 
are separated as the wasp provisions them, with plugs of clay three 
millimeters in thickness. Upon the side of the largest spider in each 
cell, a three-millimeter egg is deposited. It is slightly bowed, just 
enough to fit the curve of the spider's abdomen, slightly elongated 
at one end and about the color of skimmed milk. 

The three cells vary considerably in size. One measures three 
inches, another two, and the third is an inch and three-quarters long. 
For these differences I can see no reason. So long as there are three 
cells in the tube the wasp is apparently quite satisfied to place her 
divisions at random. 



THE WHITE-FOOTED WASP 43 

The egg hatches in forty-eight hours, resulting in the character- 
istic wasp grub of thirteen segments. It commences feeding at once 
upon the stored spiders, first drawing off the soft parts, and later 
returning to less delicate food. During the first day of its life the 
larva grows only two millimeters. On the second and third days it 
averages five millimeters each. On the fourth day it goes back to 
two, grows eight on the fifth and finishes with a growth of one milli- 
meter on the sixth and last day of its meal. The spiders are now 
entirely consumed and the grub measures twenty-six millimeters in 
length. 

Without pausing for a moment to rest, the full-grown larva now 
sets about to lay the foundations of its elaborate cocoon. The insect 
is awkwardly placed at the outset, living as it does in a cell whose 
perpendicular walls are several times its own length, but fortunately 
at this period of its life it is endowed with an unusually tacky skin. 
This stickiness serves a special purpose, enabling the grub to remain 
safely in the top or center of its cell without the slightest danger of 
tumbling down to the mortar plug separating it from the cell below. 

From its lofty position and in total darkness, the grub first throws 
out several bands of silk, fastening them in various places about the 
reed walls. It makes no choice of its own, but simply fastens each 
successive thread to the first point of contact. Some of the strands 
pass to points above the spinner, some below, and still others across 
the middle of its body to the wall beyond. At length the grub finds 
itself more or less enclosed in a delicate silken net through the strands 
of which it may still poke its head. 

Thirty or forty new threads are now extended from the top of the 
growing cocoon. They emerge from various points in a circle, and 
are fastened to the cell wall above. The larva now returns to its 
original network, within which it spins a firm torpedo-shaped cover- 
ing, slightly wider than its own body, nineteen millimeters in length 



44 INSECT BEHAVIOR 

and open at the upper end. Through this opening a ring of silk is 
spun, two millimeters in height, with a scalloped edge, the point of 
each scallop forming one of the thirty or more strands extending 
above the cocoon. The open top is now closed and reinforced with 
silk, the strands crossing and recrossing in every imaginable direction 
so that the cocoon now appears in the shape of a stubby cigar with 
an inverted parachute at one end. The strings of the parachute ex- 
tend above, where they are fastened to the reed, thus suspending the 
entire cradle in the center of the cell. 

The cocoon is now strongly supported from above. It hangs per- 
pendicularly in the hollow reed, head up, and no matter how the 
larva thrashes about, there is no danger of falling. Two or three 
hours after the last silken thread has been spun, the grub continues 
its work, this time coating the entire inner surface of its cradle with 
a transparent or slightly yellowish fluid. A certain amount of this 
is brushed directly upon the walls as it oozes from the creature's 
mouth, but for the most part, the grub expectorates it upon its own 
ventral surface. From here it is caused to flow over its entire body 
by a strange series of muscular contractions. The operation is re- 
peated over and over until the writhing creature is thoroughly moist- 
ened by the secretion. As the grub expands, contracts and turns its 
segments, the liquid becomes incorporated with the silk of the cocoon, 
wetting it thoroughly on the outside. 

It is a varnish with strange properties that the larva employs, — 
a sort of cement which will adhere only to certain objects. When 
secreted it is transparent or nearly so. It amalgamates at once with 
the silk and hardens in contact with the air into a skin, purplish brown 
in color and brittle, like the inner covering of a peanut. Strange to 
say it does not adhere to the larva, nor turn color until compounded 
with the other material of which the cocoon is made. 

The entire process of spinning and varnishing requires two full 



THE WHITE-FOOTED WASP 45 

days. The grub then expels a large pellet of waste, the accumulation 
of six days of feeding, in the bottom of the cocoon. This hardens 
rapidly into a solid cake in a few hours. Sixteen days later pupation 
takes place. 

Now comes the period of absolute quiet during which time the 
insect receives its color, which appears first in the eyes and gradually 
flows throughout the body and its appendages. The process requires 
some fifteen days. This is followed by a six-day period before the 
perfect insect emerges, to lay the cornerstone of a new generation. 



J 



CHAPTER V 

PARALYZED PROVENDER 

IN the black chambers of a solitary wasp's nest lie six growing 
youngsters. They are grayish, maggot-like creatures, each con- 
sisting of twelve rings or segments surmounted by a more or 
less bony or chitinous head that in turn supports a pair of sharp 
incurved mandibles. Their bodies are plump and pudgy; they 
possess no adequate appendages for locomotion and in the light their 
skins glisten, as if moistened with liquid. 

Each will eventually become a wasp, an active dominant creature 
with a delicate taste for nectar. But that is far ofif in the insect 
future, perhaps some forty days hence. They are concerned now 
only with the meals that are set before them, spiders that the parent 
wasp has selected as dainty provender. 

In each cell of the nest the mother insect deposits her bowed egg 
among the mass of spiders that are paralyzed by her sting. She 
hunts them abroad in the forest or among the fallen leaves in the 
sunny trails, discovers their hiding-place and swoops hawk-like upon 
the unfortunates. There is a struggle, perhaps, a short one; the 
wasp's sting soon finds its mark, plunges home, and in an instant the 
spider lies limply upon its threshold. The victim is not dead, in- 
stead it is only plunged into a state of paralysis that instantly binds 
the muscles fast. It cannot move again in self-defense, cannot com- 
mand the power of its legs. It is still a living thing unconscious 
of life. Thus, slightly quivering from the shock and poison, it is 
borne to the victor's nest, deposited roughly in a cell with several 

other equally unfortunate ones, sealed forever from the light of day 

46 



PARALYZED PROVENDER 47 

and abandoned as helpless living flesh for the young wasp to gorge 
upon. 

In order to understand what has just taken place, let us examine 
the victim's anatomy and structure. In outward form spiders are 
divided into two distinct parts — the cephalothorax and the abdo- 
men. We are concerned chiefly with the former, which is the first 
division of the creature, the head and thorax, as it were, combined 
in one. The central nervous system of the spider is, for the most 
part concentrated in a mass of ganglions clustered about the oesoph- 
agus. The oesophagus is a tube through which food passes from 
the mouth to the stomach. It lies in the central portion of the 
cephalothorax. That part of the central system lying above is the 
brain, from which the optic nerves and those of the biting and 
poisoning appendages arise. Lying below the oesophagus is the 
ganglion from which the nerves of the legs and palpi emerge. 

Now, strange as it may seem, the wasp knows the above paragraph 
by heart. She was an anatomist long before man. She understood 
spiders long before man understood himself. Her teacher was in- 
stinct, an immortal master. Thus in stinging her spider she is like 
the master surgeon. With a single tiny wound above, with a single 
lance below, she accomplishes the desired end. Into the spider's 
nervous center instinct guides the wasp's poisoned dart. With 
precise strokes she reaches the ganglions of her victim and spills 
her venom. Henceforth no external outrage, however great, may be 
transmitted to the brain; no volition in return will command the 
forces of protest and defense. Like a party on a broken wire, the 
spider lies helpless with the central office paralyzed! 

In preparing provender for the cells, the methods employed by the 
majority of solitary wasps are more or less the same. Yet the sting- 
poisons of different species produce two widely different effects on 
the victims. Both are doubtless forms of the same affliction; one, 



48 INSECT BEHAVIOR 

the commonest type, acts instantly, as I have just described. It 
causes complete paralysis throughout the muscles that control walk- 
ing, biting, excretion and all exterior movements of the cephalo- 
thorax, abdomen and its appendages. The respiratory system ap- 
pears to be all that is left uninjured. 

The second form, which is much more rarely met with, is a gradual 
type, commencing with the deadening effect of heavy sleep, finally 
giving place to paralysis, some time after the victim is stricken by 
the sting. Let us observe the two cases in question. As an example 
of the first we have a medium-sized spider that has been stung by 
the white-footed wasp. Of course different kinds of spiders are 
selected by different species of wasps. But this is of no consequence, 
and will not affect the essential facts of our observation. If the 
creature is a spider it matters not in the least whether it be Gastera- 
cantha, Filistata, Micrathena or any other jaw-splitting species. 
Spiders are the common prey of many solitary wasps, a fact which 
is sufficient. 

The victim lies limply upon its belly in the cell. Enclosed in a 
tomb of solid masonry, it is abandoned by the mother wasp to its fate. 
Upon its flank lies the glistening egg of the slayer. Thus the un- 
conscious living incubator awaits the pleasure of the maggot. Its 
legs are limp and motionless, its palpi equally still. To all intents 
and purposes the dejected object is dead, but there is still a flutter of 
life in the outraged body. An occasional shudder, barely discernible 
under the lens, a labored rise and fall of the abdominal walls evi- 
dences the tiny spark still unquenched. 

In two days the young wasp emerges from the egg, glues its mouth 
to the plump spider and commences to draw the victim, drop by 
drop, into its own body. In twenty-four hours a shriveling sets in. 
Like a punctured balloon in the sky, the spider shrinks before the 
maggot's onslaught. Later, in order to taste sweeter fare, the 




As they appear at close range 

Two common bugs which do great damage to squash and pumpkin vines. Both the insects shown above are 

immature, the lower one being the common squash-bug in its dotted youthful costume 

Enlarged four times 



^ -^ 



PARALYZED PROVENDER 49 

ravenous object plunges its head within the breach. It drinks, 
munches and revels in the spider's anatomy; eats from the inside 
to the out, chews up the bony walls, continues through the cephalo- 
thorax and finally consumes the legs. Then finding no more it 
pauses. After five days of orgy it is time to digest. Thus the spider 
is eaten alive, but from the first there is never a sign of protest, never 
a twinge of pain. 

As an experiment, I secured several other spiders paralyzed by 
the same wasp whose grub I have described at its meal, and subjected 
them to various tests. One I denude of its legs, clipping them ofif 
at different lengths, thereby cutting through eight different nerves. 
From the second I clip the palpi, severing the nerves, and into the 
abdomen of the third I thrust a slender needle. Throughout these 
gross indignities the spiders lie quite motionless. There is no con- 
tracting of leg stumps, no drawing in of injured palpi, no quiver of 
punctured body. There is no response, no feeling in the creatures. 

Such is the first condition of paralysis. We find it in a host of 
victims. The white-footed wasp, the blue huntress, the black reed- 
wasps and many others go in quest of the spider, another wasp takes 
frog-hoppers, still another, locusts, and there are many others that I 
will not mention. They are a merciful crowd. Under the re- 
spective jaws of their grubs, the victims lie completely paralyzed, 
relieved from the tortures of gradual execution. 

The second form of paralysis is, as I have stated, much more rarely 
met with. At the present time I know of only two wasps that afflict 
their prey in this manner, but they will do very well as examples. 
One is the roach-killer (Chapter III), which stores her earthen cells 
with wood-roaches, the other, a tiny, unidentified wasp that supplies 
her maggots with a cricket each. Her nest is a hollow reed lying 
upon the ground, the end of which she plugs with a great quantity 
of wood — little chunks of charcoal from the cane burnings, bits of 



50 INSECT BEHAVIOR 

reeds, tiny twigs and woodchips barricade her doorway. Therefore, 
for convenience sake, I will call her the lumberess. 

The modes of life of the two insects are in most respects widely 
at variance. They build individual types of nests, provision them 
differently, choose different situations for the home site and go about 
their respective businesses in separate ways. It is important, how- 
ever, that the two have a single habit in common. The roach victims 
of one and the cricket prey of the other are affected in the same man- 
ner by the stings of the two insects. 

I have before me two crickets of the lumberess and a dozen roaches 
of the roach-killer. These I collected from the sealed nests of the 
insects. Therefore, to the best of my knowledge they have been 
stung by the two wasps, I find in the victims a physical condition 
entirely different from that existing in the spiders paralyzed by the 
white-footed wasp. So differently are they affected that I do not 
consider them paralyz(£d at all. 

The roaches are capable of moving every pair of legs, they can 
turn the head from side to side, also move all the mouth parts and 
their antennae. But strange to say they lie motionless unless I touch 
them with a needle or the tip of my pencil. I place one of the roaches 
upon its feet. It lies absolutely still as though dead until I touch 
one of the protruding appendages at the posterior end of its body. 
As I do so it jumps forward without much effort, in the act, using 
each pair of legs. Now it waves its antennae back and forth for a 
few seconds, wriggles its mouth and settles back into its torpor. With 
the crickets I try a similar experiment with the same result. Much 
the same thing appears to take place in these victims as one observes 
in a sleeping dog, whose foot has been tickled with a straw. It is 
quite peaceful and unconscious, yet its nerves and muscles respond 
automatically to rid the animal of its annoyer. 

Certainly then, the insects are not paralyzed at this time, any 



PARALYZED PROVENDER 51 

more than a sleeping dog, for paralysis means the loss of power 
to contract the muscles, an accomplishment of which both the roaches 
and crickets are still capable. 

Twenty-four hours later I experimented again upon my subjects 
with a result similar to that of the previous day. I let another twenty- 
four hours pass. This time, at the touch of my pencil point, the 
insect responded with a jump far less energetic than before. Every 
hour now brings a weaker reaction; at length there is little or no 
response to my efforts. 

The sting of the roach-killer and that of the lumberess thrust their 
victims into painless sleep. The poison's action is not unlike alcohol. 
At first a powerful sleeping potion followed by a gradual, ever- 
increasing tying of the muscles, until they cease to move at all. Such 
is the second condition of paralyzed provender. 

Let us now endeavor to discover the causes leading to these two 
distinct types of paralysis as we have observed them in the prey of 
solitary wasps. Having already glanced at the spider's anatomy, it 
will be well for the sake of comparison, to look into the anatomy 
of the roach. In the first place the two belong to different phyla; 
one is an arachnid, the other an insect. Therefore they will differ 
physically. 

In the spider we find the ganglions clustered about the oesophagus, 
concentrated into one particular section of the body and easily ac- 
cessible. In the roach they are spread, more or less, throughout the 
insect. There is a brain, three pairs of ganglions in the thorax, 
followed by six pairs in the abdomen, a problem indeed for the wasp 
who would paralyze such a complicated creature. 

I have not been fortunate in observing either the roach-killer or 
the lumberess in the act of stinging their prey, but here is what I 
believe to be the case in view of the facts: To reach the isolated nerve 
centers at the outset, to bring instant and complete paralysis to her 



52 INSECT BEHAVIOR 

victim, the wasp would find it necessary to drive her sting into as 
many different places as there are ganglions. Judging from the con- 
dition of the prey it is a feat quite beyond either the roach-killer or 
the lumberess. Therefore they must depend upon one or two thrusts 
to stun the insects. As the sting plunges home it ejects a tiny drop of 
poison which gradually spreads throughout the victim's body, bring- 
ing on, in due time, the gradual paralysis that we have observed. 

Gradual paralysis would appear to be dangerous to young wasps. 
They are very tender creatures. A cricket or roach thrashing about 
within the cell would soon cause fatal bruises, but nature has looked 
out for them nicely. If undisturbed, the roach and cricket lie quietly 
enough. Upon their lower surfaces lie the wasp's white eggs, but 
they are motionless. In forty-eight hours the wasplets emerge, tiny 
creatures, three millimeters in length, whose baby mouths do not 
disturb the sleepers. In another day they begin to really chew their 
hosts, but by this time paralysis has set in. 

There is no significance in the two types of paralysis. They are 
present in the spider and the roach, simply because of the physio- 
logical difference existing between the two. Thus the grubs of the 
roach-killer and the lumberess and those of the spider hunters live 
much the same. One is as safe in its respective cell as another, so 
there we shall leave them. 



CHAPTER VI 

THE FOREST SHELL-WASP 

Zethusculus hamatus Zav 

HOW early one thing begins to support another in the jun- 
gle! Even the infant, thread-like air root, new born from 
the parent liana, sustains a spiral of fairy moss and later 
a tiny emerald wasp's nest, fashioned from the ribbon 
of the sporophyte. The great cool jungle reminds me of a jig-saw 
puzzle, the pieces of which are its life, entwined and ingrown, each 
using another for its own particular success and to complete its part 
in the great green picture. A giant liana supported by a still greater 
tree; thread-like offspring supported by the liana, fairy moss living 
upon the thread-roots, wound in its turn into the hoop-like walls of 
an insect nursery. Here at least are five fragments of the great puz- 
zle we see fitted together. 

The nursery which belongs to the shell-wasp of the forest reminds 
me of two algae-grown snails, one clinging to the slender stalk, the 
other to its sister's tapering shell. In reality, the two shells are the 
cells of the nest fashioned from the ribbon-moss which grows upon 
the air-root. It is very delicate material. One must, look sharply 
in order to see that it is a thing separate from the mere thread that 
supports it. Peeling o& the ribbon, the wasp winds it into little 
hoops, one upon the other, and cements it together with her own per- 
sonal glue. The building material, when dry, is tough and quite 
waterproof. Some twenty hoops, half a millimeter in width, com- 
plete each cell, and the freshly made nest gives off an emerald sheen. 

53 



54 INSECT BEHAVIOR 

In each cell a stumpy, slightly bowed egg is laid, two and a half 
millimeters long and a third as wide. It is yellow in the center, 
fading to a transparent white at either end. The yellow center is in 
reality the young wasp, and the transparent end, the extremities of the 
film-like egg shell. The eggs are laid one at a time, that is to say, 
the wasp deposits in one cell, waits for it to hatch, then provides the 
young with sufficient food to bring it to maturity and plugs the cell 
with moss before laying the second egg. 

Its chosen prey is doubtless small caterpillars, for I found three 
uneaten heads in a cell containing a full-grown larva. The egg is 
attached to the roof of the cell by its posterior end near the back, and 
hangs downward. Thus the young wasp hatches with its head in 
mid-air. 

The mother wasp guards her cells closely during the period of 
incubation, often resting within the cell containing the new laid egg. 
She crawls to the entrance on the roof of the nest, then turning round, 
backs in, clinging to the underside of the roof. Her head peering 
out, with its antennas waving here and there, adds to the illusion of 
the nest being the shell of a snail. 

The two nests on which this life history is based were found on 
May 14, in the deep forest. One of them I lost, but let us go back 
to that day and the remaining nest. If I leave it upon its swaying 
air-root for further observation, I will probably never find it again. 
It blends perfectly with the emerald surroundings, a tiny object in a 
part of the forest that I have visited but once. Therefore I will 
carry it home to the laboratory just as it is, and put myself in diffi- 
culties at once. 

The first cell contains a full-grown larva and the second is empty, 
save for a single, freshly deposited egg. The larva is quite satisfac- 
tory. It has finished its meal of caterpillars and will soon pupate, 
giving me much desirable information and no trouble. But what of 



THE FOREST SHELL-WASP 55 

the egg? If true to the rule, which is usual among solitary wasps, 
it will become a hungry living grub in forty-eight hours, how then 
shall I feed it? I have not given the parent wasp a chance to store 
provisions for her larva, yet I am responsible for the orphan. 

The young of solitary wasps are fed on a variety of material, but 
spiders and caterpillars seem to be most frequently chosen as prov- 
ender. This I know from experience gained in the examination of 
a great many nests. In the light of the present difficulty it may prove 
a valuable bit of knowledge. The victims are stored within the cells 
in a paralyzed condition from which they never awake. If they 
were killed outright, they would soon putrefy in the cells, contam- 
inate the budding wasps and turn the healthy nursery into a colony 
of lepers. Therefore instinct, the great teacher of insects, guides the 
wasp's sting only into the victim's nervous centers. The creature 
so treated, passes into a comatose condition and lies powerless to 
move or struggle while the young wasp sucks at its viscera. This, 
then, is my grewsome course: I must catch, artificially paralyze and 
present living food to the shell-wasp's grub if I am to rear the orphan 
successfully. 

A search for caterpillars of the proper description is entirely 
unsuccessful. They must be minute, soft, and without hair upon their 
bodies or the youngster will die of indigestion. Moreover it is the 
off season for them and unlike the wasp I cannot find them by the 
sense of smell. Therefore as an experiment I substitute spiders for 
the proper diet of span-worms. Spiders are abundant and easily 
paralyzed. 

The nervous system of a spider is concentrated in a mass of gan- 
glions gathered about the oesophagus. It lies in the cephalothorax, 
or in that section of the creature which is foremost, there being but 
two divisions. 

I secure my first victim from its web in the window corner. It 



56 INSECT BEHAVIOR 

is a long-legged creature with a good plump body, soft and unpro- 
tected. With a little chloroform, I anaesthetize it, just long enough 
to keep the creature quiet. As soon as it is still, I clip its legs ofif 
quite short, then with a very slender needle I stab the cephalothorax 
in two places, once from above, once from below. My object is to 
reach the ganglions mentioned above, thereby injuring them with my 
needle and producing a sort of paralysis in the spider. The experi- 
ment works well enough. The victim quivers for a moment, then 
lies motionless. With my crude sting, represented by the needle, I 
have imitated as closely as possible the methods employed by the 
parent wasp in preparing food for her offspring. 

Now I place the spider in the cell just under the suspended un- 
hatched egg of the wasp and await developments. In two days the 
young wasp emerges from the shell, and hangs head down, still 
attached at its anal segment to the cell wall. For several hours I 
keep close watch, during which time it pays no attention to the para- 
lyzed spider. It scorns my work and the repast I have prepared and 
hangs helplessly, its mouth sucking rhythmically at the air. Now I 
move the spider so that one of the stab wounds in its body comes in 
contact with the larva's mouth. It responds frantically, like a crea- 
ture dying of thirst, to the liquid that oozes from the wound. It 
fastens itself by the mouth to its victim and there it clings like a 
suction pad, its entire body rippling as it drains the spider's life. 

Much to my surprise the experiment is crowned with success. In 
a few hours a change is noticeable in the larva — it has grown and 
gained in strength. At length it pulls away from the walls of the 
cell and settles among the spiders I have provided. It is an experi- 
ment especially prolific in answering abstract questions and suggest- 
ing others. It proves that all larvae are not entirely dependent on 
one certain article of diet. Doubtless a given species is invariably 
supplied by the parent with the same kind of food, yet we have posi- 



~4,pH 




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-a 



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t .5 



S c 

^ W 



THE FOREST SHELL-WASP 57 

tive proof that such a condition is not imperative. The larva has 
no more abhorrence for the spider than for its natural diet of cater- 
pillars. If the mother wasp but knew the truth she might store her 
nest with the ever abundant spider in years of caterpillar scarcity. 

Further, the experiment points out that in the wasp's victim, 
paralysis may be brought about by the thrust of the dart unaided by 
its poison. It is the stabbing and injuring of the ganglions that pro- 
duces the effect, at least in the case of the spider. 

Is the poison of the wasp a potion for prolonging life in the stores, 
rather than an agent for producing paralysis? Do wasps that attach 
their eggs to the cell walls, leave the doors open until the young 
wasps hatch, for any particular reason? These are questions that the 
experiment suggests. But let us go back to the insect's life history. 

At birth the young wasp measures two and one-half millimeters. 
It is a milky white grub of thirteen segments counting the head, 
which is a round bead-like affair. As it feeds and increases in size 
the distinction of the head decreases. At first the head is nearly the 
same diameter as the body itself, but the latter soon takes on flesh 
and grows many times its original size, so much more rapidly than 
the head that it soon greatly surpasses it. 

I continued to feed my orphan for five days, which is the average 
length of time spent gorging by the Guiana grub. During this time 
it consumed several small spiders that I paralyzed and placed before 
it, reaching in the end a length of seven millimeters and turning a 
pale yellow color, much like clouded or partly sugared honey. 

Now the grub lies motionless for three days, when a pellet of un- 
digested bits of spider is deposited in the cell. No cocoon of any 
kind is spun; instead it lies upon the bare hooped floor of the nursery, 
apparently quite contented. All wasps rid themselves of what waste 
has accumulated during larval life in this manner, a short time prior 
to pupation, the majority placing it in the lower pole of the cocoon, 



58 INSECT BEHAVIOR 

where it acts as a solid plug. When the waste matter is expelled the 
grub often loses its original color, which is due only to the sewage 
showing through its transparent skin. In the case of the shell-wasp, 
it changes from a clouded honey color to white, slightly tinged with 
yellow. It also becomes more opaque. 

Ten days after excretion the insect pupates. Then comes another 
wait of three weeks before the final wasp issues from its cell. 

During these twenty-one days, the pupa receives its finishing 
touches — at first, when the transformation from the larval state takes 
place, there is no dark pigment in the body. It is yellowish white 
and rather translucent. Color appears first in the eyes, which turn 
light lavender, then brown and finally black. Next, the pigment ap- 
pears in the remainder of the head. Then, as though coming through 
some hidden tunnel below the flesh, it appears as a mere dot of dark 
fluid in the center of the thorax. Slowly the dot expands, throwing 
out arms of color which later combine and fill the entire thorax with 
pigment, like a rocket that unfolds its display in the sky. Next the 
slender petiole of the abdomen becomes clouded. This soon gives 
place to darker color while its recent cloudiness appears in the abdo- 
men itself. At length the entire insect turns black save for the three 
small orange-yellow patches on its abdomen. 

This general dullness is due to the pupal skin in which the finished 
wasp is now resting. We see it through this delicate membranous 
covering which is immeasurably thin, and fits the insect as closely 
as her own external skeleton. Under the transparent covering the 
insect appears dull, but otherwise quite normal except for her wings. 
Her legs and antennae are of proper length, her head and body neatly 
proportioned, yet her wings are but a third the natural size. They 
are hollow appendages intricately folded and held in place by the 
wing bags of the membranous covering. Later with the pupal skin 
of which they are a part, these bags are shed, releasing the true wings, 



THE FOREST SHELL-WASP 59 

which unfold to their full extent under a pressure of liquid which 
flows into them from the wasp's body. Later the liquid is withdrawn 
and they dry as thin, brittle appendages. 

When the pupal membrane is cast the wasp requires at least another 
day to rest and gain strength for her emergence. She does not issue 
into the world in the wet, weak condition of the butterfly, to rest and 
dry in the sunshine before flying to seek her mate. Instead she makes 
her toilet within the cell and waits for full strength before emerging. 
Then, everything ready, with knife-like mandibles, she cuts a neat 
round hole through the mossy wall and casts herself to the lot of 
fate. 

We see her as she emerges, all glistening with the youth of a new 
generation. A scant forty days have passed since the mother wasp 
fashioned the emerald nursery upon the swinging air root. 



CHAPTER VII 

THE ONE-BANDED DAUBER 

Sceliphron fistulare (Dahlb) 

THE physiological phases of the dauber's life history natu- 
rally adhere to a set of invariable rules — the egg hatches in 
a certain length of time, the larva feeds until the spiders in 
its cell are consumed and in the course of certain definite 
periods the insect pupates and emerges. Her nest is of clay, her pro- 
visions spiders, but otherwise, in the remainder of her nesting activi- 
ties, this wasp is a creature that follows no rule. Her nursery may 
be but a single earthen cell or it may boast a group of twelve. It 
may be fastened to a twig, to the side of a house, to a sheltering stone 
or on the edge of a narrow shutter slat — one nest is a long fiat object 
humped at one end with additional cells and decorated with strips 
of variegated clay, another is top-shaped; still another is but a single 
gray cell, half circular at one end and quite round at the other. They 
vary endlessly according to the energy and taste of the individual 
builder, therefore I cannot describe any one nest as the usual type — I 
may tell only of the building of a cell. It may be the first room 
framed in an elaborate plan, or the completed nest of the dauber, 
but my remarks will apply to any nest. 

Upon a brick pillar supporting the laboratory the wasp laid the 
corner-stone of her nest. Twelve loads of brown mud, tamped out 
into flat pies, side by side, sufficed for the foundation. The material 
was carried in little round pellets weighing one-tenth of a gram. 

They were borne in the wasp's mandibles from a moist spot in a flat 

60 



THE ONE-BANDED DAUBER 



6i 



clearing nearby. Each pellet was tamped and arranged with great 
care, during which time the wasp buzzed continually and held her 
abdomen at the end of its long petiole high in the air, as a balance 
weight to the lowered head on the other end. The forelegs were used 
as much as the mandibles, thus her dumbbell-like body swung pivoted 
upon the central pair of legs. 

When the foundations were laid she proceeded with the cell itself, 
bringing thirty loads of mud per hour. In a little over two hours 
the cell was complete, a neatly rounded tube, thirty millimeters long 
and sixteen millimeters in diameter, the result of some sixty-five loads 
of mortar. 

In fashioning the tube, the first few pellets were deposited side by 
side and raised into a semi-circular mound, or half disk stood on end. 
Here again the work was accomplished with her mandibles and 
forelegs. The clay was pinched up between the tarsi and then shaped 
principally with the mandibles, which acted like a pair of flattened 
tongs. When the disk was finished the successive loads of mud were 
pressed against its inner surface, usually at one side and then moulded 
into a narrow ridge running around its circumference. Thereafter 
each pellet was fashioned into a ribbon of plaster placed against the 
side of the preceding layer. When the job was finished these indi- 
vidual layers were quite visible so that the separate rings of which the 
nest was constructed could easily be counted. 

In coming to her nest the wasp often experienced great difficulty 
in locating it. She would approach the brick pillar with her mortar 
pellet, circle the column once and then alight, as a general rule, some 
distance above or below the nest. A thorough inspection of the spot 
to which her general sense of direction brought her, would follow. 
This inspection never extended beyond one or two bricks at most. 
Finding the cell missing, she would take wing, circle the pillar once 
more and alight in a new location. Sometimes this performance was 



62 INSECT BEHAVIOR 

repeated over and over, until at length she would come by chance 
upon the brick supporting the object of her search. 

Different species of wasps vary greatly in degrees of accuracy in 
finding their nests. Some experience no difficulty whatever, others 
have slight trouble, while still others spend at least one-third of their 
nesting period searching for the elusive keyhole. So true is this 
among solitary wasps that they might be divided into several groups 
in the order of their respective accuracy. One group would contain 
the wasps which build their nests in the ends of hollow reeds. The 
home doorway may be in the midst of a dozen others, yet the owner 
flies directly to her own threshold without an instant's hesitation. 
The long black reed wasp ^ and the white-footed wasp ^ would be 
shining examples of this enlightened group. Again we have such 
wasps as the red-legged digger ^ who locates her tunnel in the ground 
only after a series of circular flights in the air above it, much as a 
carrier pigeon does upon release, before turning in the homeward 
direction. In the third group, the one-banded dauber might head 
the list of blunderers who find their cells only after a search, some- 
times of great length, with the loss of much valuable time and energy. 

I do not believe that sight is an important factor to be considered 
in any of the above cases. Most insects do not see such small objects 
as their nests clearly from a distance. It is, to some extent, a sense 
of smell, after the main journey has been accomplished, but they 
rely chiefly on a sense of direction. Some have it more highly de- 
veloped than others, just as the Indian finds his way in the forest un- 
aided by compass, where another individual, a white man, would 
fail or perhaps blunder through to his camp. The one-banded dauber 
flies accurately enough to her brick pillar, but lacks that balanced 

^ An unidentified species of Trypoxylon. 
^ Trypoxylon leucotrichium (Chap. IV). 
^ A species of Sphex. 



THE ONE-BANDED DAUBER 



63 



sense of direction that lands the white-footed wasp in a single flight 
at her doorway. 

In the wooden shutters of the laboratory, I found further evidence 
of the dauber's stupidity. For a nesting site, she had selected in 
this case the narrow edge of a slat, situated midway between the top 
and bottom of the shutter. Below her site were a dozen other slats, 
each affording a building plot similar in every way to the one she 
had selected. Above her were as many more. This made her work 
difficult; as it finally proved, too difficult for her limited sense of 
direction. She laid the foundation of her nest in a maze of sites, 
each exactly like those above and below, and in the end her design 
perished. Her pellets of mud were deposited upon four different 
slats, one below the other, until four different cells, three inches apart, 
commenced to take form. Arriving laden with her ball of mud she 
would fly to the general location of her original foundation, but to 
distinguish which slat among so many similar ones supported her 
original masonry was quite beyond her. Thus she worked, vainly 
endeavoring to finish her nursery in the usual space of time, laboring 
the while on four widely separated cells! Eventually she abandoned 
the job in despair, and indeed it must have been discouraging. To 
return, hour after hour, laboriously carrying that heavy mortar to 
a house that refused to grow, might easily discourage a stouter heart 
than the dauber's. 

That she concentrated her efforts entirely upon four slats was an 
interesting fact. It gives us some idea to what degree of perfection 
her senses of smell and direction are developed. The first slat bear- 
ing evidences of her workmanship was situated twelve inches above 
the fourth and lowest one. Now as the wasp always returned, with 
her pellets, to one of these four, it is logical to suppose that her 
sense of direction was developed accurately enough to bring her 
within twelve inches of the actual location of her nest. Observation 



64 INSECT BEHAVIOR 

of the insect whose nest I found upon the brick pillar strengthened 
this evidence. This wasp never returned directly to her nest at the 
outset, but at the same time never alighted with her burden more 
than a full twelve inches from it. From such a position she would' 
walk about in a zigzag course, until at length the brick bearing 
the nest was reached. Once this "home brick" was located, the insect 
would walk straight to her nest. The dauber returns to the general 
locality without much difficulty, but actually to reach the cells she 
must feel about with curled antennae, and depend upon smell rather 
than a mere sense of direction. 

To build a cell, including its foundation, requires between seventy 
and eighty loads of mortar. The freshly made nursery weighs about 
seven and two-thirds grams, but by the time it is ready to receive 
provisions, evaporation has reduced it to three. From these figures 
I conclude that to build a nest containing ten cells requires some 
seven hundred-pellets of mud. In accomplishing her task the tireless, 
energetic mason carries i,ooo times her own weight in mortar and 
fashions it grain by grain into the abode for her progeny. 

In storing her cells, the dauber shows a varied taste. I have before 
me two open cells. One contains two large fat spiders that easily 
fill the storeroom, the other is stored with a variety of victims, nine 
in all, including many grades of size and color. In these two cells I 
have at least two genera and five different species of paralyzed 
spiders. 

Upon the side of the abdomen of the largest one in each cell, the 
wasp deposits a pale yellowish white egg, then she seals the nursery 
entrance with a few pellets of mortar and abandons the nest for good. 

In seventy-two hours the egg hatches, or I should say, comes to 
life. Here is a strange process. Watching the erstwhile egg through 
the lens, a spasm suddenly takes place within its film-like shell, which 
is nearly transparent and allows a fairly clear view of what takes 





One-banded dauber freshly emerged from her cocoon. 
Enlarged twice 



Suspended hatching egg of the forest shell-wasp. En- 
larged seven times 





V 


K.^iSjM- * 1 . '• , 




f :< ^V^ 






- / ■ ' 


^ ■ ■■%• 




\ 


"'. 




■ 


^ -— \ -. : - - ..>.^ 




..^^rJfe;;;- .. . -:- :- 


.,,._„^ _„,,-..—■: 




One-banded dauber working upon her nest. One- 
third natural size 



Four types of nests made by the one-banded dauber. 
One-third natural size 



THE ONE-BANDED DAUBER 65 

place within. This spasm is a sort of pumping wave, similar to the 
movement in a big fire hose under pressure from the engine. It 
starts at the anterior end of the egg and traverses its entire length, 
fading out as it reaches the opposite end from which it started. Thus 
does the new-born take its first mouthful of liquid food from the 
spider. There is no actual hatching and crawling forth from the 
egg, no empty shell behind the larva. Instead, its mouth appears 
first to eat a tiny opening through the film that encloses it, after 
which the grub finds its mouth flat upon the spider's abdomen. As 
the pumping spasms continue, each one representing a swallowed 
mouthful of spider substance, the nursling increases very gradually 
in bulk. In a few hours after taking its first draught of foodstuff, 
the egg-film apparently splits along the center of the larva's back, 
one end of the breach traveling in either direction, exposing the 
actual skin of the young wasp. The breach spreads like a drop of oil 
upon water, only much more slowly, but twenty-four hours after 
the first spasm not a vestige of film remains. It appears to have been 
absorbed into the larva's body. Under the lens it vanishes slowly 
before my eyes, yet I cannot see where it goes, and when the process 
is over I can find no trace of it, either on the larva or its spider host. 
The grub is a living dialyzer through whose delicate skin the egg- 
film appears to osmose. In other words, I believe that the film is 
absorbed into the insect's body in minute particles in much the same 
manner that food passes through the walls of the oesophagus to reach 
the distributing corpuscles. 

It is possible that the larva eats the egg-film, but if so it is drawn 
into the mouth so gradually and with such skill that it is impossible 
to detect the operation. Therefore, I suggest that the process may 
be akin to osmosis. The action is so gradual, so smooth and unin- 
terrupted that I can think of no other way to describe it. 

At first the young wasp lives only on liquid foods. During the 



66 INSECT BEHAVIOR 

first few hours of its life its mandibles are of a very rudimentary 
character, in fact scarcely distinguishable until the grub is a day or 
more old — and are developed gradually to be in readiness later when 
substantial parts of the spider must be eaten. The fact that at birth 
the grub possesses no adequate appendages for chewing suggests an 
interesting question: How does the tender creature make the first 
incision through the mature wall of the spider's abdomen? Perhaps 
the parent wasp pricks it and uses the minute drop of fluid that oozes 
from the wound as mucilage with which to secure the position of her 

The grub feeds for six days — during this time it goes about its 
meal in a thorough manner so that in the end not a hair of the stored 
spider remains. Further the larva has changed greatly in size. At 
birth it measures four millimeters, now it is seventeen millimeters 
long and ready to spin its cocoon. 

Spinning is a laborious process requiring three whole days.- A 
slight network of silk is first thrown about the cell, within which 
an inner cocoon of a far more substantial character is then con- 
structed. It is somewhat longer than the grub, torpedo-shaped and 
reddish brown in color, which is due to the varnish, so commonly 
employed by the larvae of Hymenoptera, showing through from the 
inside. 

The cocoon is in no way remarkable, in fact it is quite simple. I 
have seen other larvae build more elaborate ones in a day, yet the 
dauber requires seventy odd hours for so simple an operation. Its 
nature is sluggish from the outset, and throughout its immature life 
it is slow about its affairs. The egg requires three days to hatch, the 
grub feeds six days, therefore it logically follows that spinning should 
be a leisurely process. Consequently, the grub takes its time and 
is none the worse for it. 

Seven days after spinning, pupation takes place. The creature now 



THE ONE-BANDED DAUBER 67 

lies motionless in the usual quiet state that accompanies this condition. 
Colorless and stately, lying upon its back with folded arms in its 
tomb of masonry, the pupal corpse awaits a reincarnation that in 
twenty days brings forth a perfect insect. 

Stupid affairs of the wasp world are generously heaped upon the 
dauber. Before me lies an oddly-shaped nest of her making which 
I have opened for inspection. It contains twelve cells and as many 
cocoons, ten of which have been burst open by the young wasps who, 
alas, lie dead and shriveled in their cells. Their heads face the 
mortar-plugged doors of the prison, which bear marks of frantic 
efforts to escape, yet each has died of starvation, unable to reach the 
outer world. 

Herein lies the reward of stupidity. The dauber, whose life seems 
made up of errors, chose for her nest the first mortar that she chanced 
to find. It was not soft gray mud from a puddle, or the sandy orange 
surface of the clearing, but a pasty yellow clay. It kneaded ad- 
mirably when soft and fresh but in hardening turned to rock. The 
offspring grew normally within, spun their cocoons and passed suc- 
cessfully to finished insects, but were unable to emerge. They ham- 
mered and gnawed and scraped at the mortar; the nest bore evidence 
of the effort put forth, but all in vain. The mortar resisted and the 
young wasps died. Thus on the very eve of their emergence the 
dauber's offspring were obliterated by her stupidity. I wonder, 
even if there were a tiny glimmer of intelligence in her little dome, 
whether she would see the error of her ways? 



CHAPTER VIII 

THE BLUE HUNTRESS 

Chlorion neotropicus, Kohl 

CLOSE to the out-house, whose rough frame supports the 
nursery of the blue huntress, lies a heap of rich red-orange 
clay, thrown up from a pit on the trail to the forest. It at- 
tracts a dozen busy mason-wasps who arrive from far and 
near to gather up the pliable, ready-made mortar and bear it away 
to their nests. We are concerned only with a single member of the 
laboring crowd. She is at once distinct in size. Her rich metallic 
color attracts our attention and holds it over eleven less comely ones. 
The cement which she is gathering is pliable like putty, but filled 
with tiny bits of stones that make its contents similar to that of very 
fine concrete. These tiny stones, which are large rocks to the insect, 
lend themselves admirably to the needs of her nest. They lend a 
rough, rugged appearance to the three-celled nursery, but form an 
impregnable barrier against a host of enemies. 

The building material is laid on in irregular heaps. They dry 
■ very rapidly as the work progresses, giving the nest the appearance of 
a bit of fairy hill country covered with a thousand disorderly loads, 
spilled helter-skelter from as many tiny dump carts. The wasp cares 
little for outside appearances, which are of no account. She is con- 
cerned chiefly with finishing the interior, which is a far more serious 
matter. 

Within, the cells are quite as smooth as they are rough without, a 
condition necessary in view of the delicate contents they are to 

68 




Spider prey of the blue huntress, showing egg of the wasp attached to its abdomen. Greatly enlarged 




Pupa of the blue huntress, showing T-shaped jacks, which support the creature's abdomen, thus protecting its 

legs. Greatly enlarged 



THE BLUE HUNTRESS 69 

shelter. The slightest projecting bit of stone work, even a sharp 
grain of sand overlooked, might injure the tender bodies of the in- 
sect's offspring. Thus v^e see her tamping a tiny pebble or a bit of 
hardened mortar, until it sinks into the smooth wall of the chamber. 
Over and over, she inspects her work, scraping, brushing, tamping, 
until the cradle bears no resemblance, except that of color, to the 
coarse, sticky substance from the pit. Her nest reminds me of a 
callow suburban home, terra cotta and jagged stones. Her taste is 
not cultured, but we may excuse her quite readily. She specifies these 
droll materials for a vital reason. 

The huntress is a skilled worker — she is a prodigy, requiring but 
a single tool to fashion the mortar nursery. The tip of her abdomen 
is a veritable tool chest all in one, a universal appliance with which 
the work is done. True, she gathers and carries material with her 
mandibles, but the house itself is wrought by the last segment of her 
body. It is a modeler's gouge, with which she measures the cells, 
decides their contour, smooths their walls and fashions the entrances. 
Throughout the building one finds tiny, triangular indentures, where 
the tool has left its impression. 

The finished nest consists of three tubes, placed one upon another. 
They are open at one end, where the entrances are slightly funnel- 
shaped like the mouths of flower vases. The tubes or cells measure 
thirty-four millimeters in diameter. There is variation to a slight 
degree, but the measurements are the average of several nests. The 
insect works energetically, completing the work in five days. One 
cell is constructed, provisioned and an egg deposited, before a second 
one is commenced. 

As soon as a cell is finished, the wasp sets out in search of pro- 
visions with which to assure the successful life of her offspring. She 
travels the open sunny trails, or the dark floor of the forest. One is as 
good as another, provided there are dead leaves or fallen branches 



70 INSECT BEHAVIOR 

that shelter her prey from less agile creatures than herself. We see 
her alight upon the ground and search diligently under every leaf 
and branch that chances in her path. Her antennae are curled over, 
so that the end of each forms a perfect loop. She thrusts them ahead 
of her and depends upon their sensitive pores to locate the big tawny 
spiders that constitute her prey. She is always nervously alert, her 
body tense and ready at an instant's notice to spring back out of 
danger. As she works, her big, steel blue wings quiver continually 
as though with excitement over the possibilities of each new leaf and 
shelter that she explores. 

Her course is irregular. Here she searches for perhaps a minute, 
followed by a longer investigation some fifty feet away. Now the 
hunt leads her back to the starting point and later to the intervening 
ground, which is searched minutely. At other times she walks in a 
zigzag fashion for a great distance, even though unsuccessful in the 
end. It is a surprise to me that she finds her elusive and protectively 
colored prey at all. You wonder why? Then search among the 
leaves for the spider that serves to provision her nest. You will 
scarcely find one, even in a whole day's hunt, yet the huntress is a 
dominant insect, seldom defeated in her quest. 

At length the spider is found lurking beneath a brittle leaf. Her 
antennae telegraph the information to a tiny brain and instantly the 
wasp springs back as though surprised. A second later she recovers 
and thrusts herself into the spider's den. Her body bends under 
her so that the deadly sting protrudes almost beyond the head. At 
the first movement from the spider, she springs back again with 
quivering wings. The manoeuvre is repeated over and over until 
her prey is at length, forced unconsciously into a convenient position^ 
Then, like a flash, she is upon the unfortunate. Her sting plunges 
deeply into the creature's nerve center and instant paralysis results. 

The spider is not killed outright. In that case it would decompose 



THE BLUE HUNTRESS 71 

and become dangerous fare for the young wasps. Instead, it is 
simply paralyzed. It will never move again to protest, or protect 
itself. Perhaps it may react automatically with a slight quivering of 
the legs when touched, but henceforth it will yield to whatever fate 
has in store for it. The victim will awake from unconsciousness only 
as a part of another living creature, when spider substance has been 
eaten to build the body of a wasp. 

The spider is a larger creature than the wasp herself, yet she 
manages to fly laboriously to her nest, carrying her victim by one 
of its palpi, clasped between her mandibles. To gain access to her 
nest, she must enter the outhouse through a slatted window, the lowest 
part of which is three feet from the ground. Once she missed the 
opening and tumbled with the spider headlong to earth. She was 
undismayed by the fall, never once relinquishing her hold, but I 
was struck by the difficulty she experienced in starting once more 
for the opening. It required the combined strength of legs and wings 
to drag the creature up the perpendicular wall of the building to the 
slats of the window. 

Once within, the spider is dragged to the waiting cell, where it is 
left with head facing the entrance. A yellowish white egg, projectile 
shape, is now deposited upon the side of its abdomen. This accom- 
plished, the wasp returns to the outside of the nest. Now comes a 
thorough personal clean-up before continuing. The forelegs are 
drawn through her mouth and rubbed briskly over her head and 
antennae. The hind legs are used in cleaning the wings and abdomen 
and during the process the wasp stands almost upon her head. In a 
few minutes she is clean and bright. Doubtless the scrubbing re- 
freshes her, as a bath puts new vigor into a tired man who has worked 
faithfully for his family and returned home with the sweat of labor 
still upon him. 

But her work is not over with the storing of the spider. She has yet 



72 INSECT BEHAVIOR 

to close the cell with a seal that cannot be easily broken. The job 
must be done with care, and quickly. A flaw, ever so tiny, in the 
masonry, may jeopardize the helpless inmates. Wasplets are tender 
morsels, fine fare for many a parasite. The huntress must guard the 
results of her labor. I watched this interesting process, which re- 
quired an hour from the time the spider was dragged into the cell. 
It was only a tiny doorway, ten millimeters in diameter, yet during 
those sixty minutes, thirty loads of clay were brought to the nest and 
packed with minute care into the entrance. The tiny trowel and 
scraper, the tamper and smoother, all combined in the tip of her 
energetic little body, must have been worn indeed when the task was 
finished. But there was no sign of fatigue. In fact, I believe she 
rejoiced at the close of a day, well spent in the interests of her race, 
without a thought for her own spent body, for such is the great spirit, 
altruistic even though unconscious, that rules the insect world. 

The last cell provisioned and sealed, the wasp abandons her nest. 
She deserves a rest and a feast of nectar. Henceforth, nature will 
take charge of her offspring that she may spend her declining days 
unburdened. 

Within the cell, the egg hatches in forty-eight hours. In place of 
the tiny albumen filled projectile, we have a soft white grub. It is 
footless and quite unfitted for anything but the consumption of food. 
It possesses no sting like the parent huntress, and could not compete 
in battle with the most primitive insect, yet it feeds, immune from 
danger, upon the spider that lies limply within the cell. Like a 
foundling, the wasp in its infant state is reared by a foster parent. 
Like the child, it lives only upon liquids, drawing them from the 
huge bosom of its spider wet-nurse. As the draining goes on the 
spider's body shrivels accordingly. In forty-eight hours the pap is 
exhausted, but now the grub is strong enough to partake of solid food. 




w 



a. o 



c £ 



THE BLUE HUNTRESS 73 

Its mandibles are capable of masticating what remains of the feast. 
In short, it sips the cream first and eats the porridge afterwards. 

After five days of continuous gorging, the larva treats itself to a 
short rest before spinning its cocoon. During the five days, the spider 
has vanished so completely from the cell that only a microscope re- 
veals a few uneaten hairs. These adhere to the larva's tacky skin, 
and thus escape the stomachward journey. I have never seen such 
a hog! Long after the feast is over, when the dishes have been licked 
clean, so to speak, the glutted one continues to Fletcherize upon 
the air. 

The act reveals how hard and fast are the instinctive rules govern- 
ing the insect's behavior. The larva hatches upon the spider's body. 
As soon as its mandibles become strong enough, they commence to 
tear and chew automatically. A bit more or a bit less provender in 
the cell is of no consequence whatever. Once started, the jaws con- 
tinue to work for a certain set length of time that allows for variation 
in the bulk of the stores. Thus, if the spider be a bit large, it will 
be consumed readily enough. If a bit small the larva will simply 
continue, as I have said, to Fletcherize upon the air until the time 
limit set upon the active period of its mandibles is up. The insect 
is an automaton, a slave to a power that is not intelligence. 

As an experiment, I introduce two spiders into a cell where one is 
the normal provender. The larva consumes nearly all of the feast, 
grows to an abnormal size, but eventually dies. This would appear 
to contradict the existence of an invariable set of rules governing the 
insect's life, but such is not the case. I have interfered in the normal 
course of events and artificially changed those rules at the outset by 
doubling the amount of provisions in the cell. The wasp's life is like 
a chemical compound, the ingredients of which correspond to these 
rules and depend upon one another for the ultimate result. Thus 



74 INSECT BEHAVIOR 

if we alter the quantity of one ingredient the desired result is not 
obtained. 

The experiment has in no way disproved that the creature's life 
progresses by hard and fast rules. On the other hand, it confirms the 
statement, and further, points out that each rule depends upon the 
invariability of another for the ultimate success of the wasp. It 
also tells us that feeding is governed by the amount of provisions in 
the cell. Each mouthful stimulates a certain number of strokes from 
the mandibles. Thus, when the normal provender is consumed by 
the larva, it still continues to chew until the stimulus is gone. In the 
cell containing two spiders, the poor wasplet found no end of good 
things. It ate one spider. Its mandibles continued toward the limit 
of their working hours and came bump into the second spider. The 
stimulus was renewed, and its jaws commenced to work again, event- 
ually dragging the unfortunate larva into death at the hands of in- 
digestion. 

Thus we see the reason for hard and fast rules among insects. They 
are entirely dependent upon them for their existence. Even so slight 
a variation as my experiment provided, proves this to my satisfaction. 
I varied the rule in one small particular with the result that the larva 
was led unconsciously to its own destruction. 

To go back; the larva upon finishing its spider rests for a short 
period before commencing its cocoon. This rest may be necessary 
because there is nothing else to be done until the spinning fluid of 
which the cocoon is to be made, commences to flow. Once started, a 
network of strands is thrown across the cell. They pass for the most 
part under the spinner so that the grub rests upon a net, stretched 
midway between the top and bottom of the chamber. Later, upon 
this preliminary support, a neat tubular cocoon is spun. It is rounded 
at both ends, grayish yellow in color, glossy and rather transparent. 
It measures eight by seventeen millimeters, and only partly fills the 



THE BLUE HUNTRESS 75 

roomy cell. As a final touch the interior is lightly coated with a 
pale, smooth varnish. The cocoon is finished in two days, after which 
the larva excretes a mass of waste matter in one end. This accom- 
plished, it lies quietly awaiting pupation, which follows in eight 
days. 

The pupa is yellowish white and beautifully folded so that its re- 
markably long posterior legs do not extend beyond the tip of its 
abdomen. Its head is armed with four spikes. Upon either side of 
four of the six abdominal segments there is a "jack," or protruding 
T-shaped support, and protruding from the opposite sides of the 
lateral segment is a pair of club-shaped appendages. 

At first I took these strange objects to be the remains of ancestral 
legs. I thought them inherited rather than acquired characters, but 
continued observation of the pupa within its cocoon proved the con- 
trary. They have been acquired in order that the insect's heavy abdo- 
men may be kept leveled or centered within the cocoon, no matter 
how it is shaken about or turns of its own accord. 

This is very important to the insect. It is not that the pupa would 
be injured by contact with the cocoon wall, but rather that the weight 
of its own abdomen, which is joined to the remainder of its body by a 
very narrow waist, would have to be borne by the creature's tender 
legs. In such a case they would become partly crushed and, owing 
to their great delicacy at this period, would not develop properly. 
When the legs have become strong and have received their steel-blue 
pigment, all the supporting appendages shrivel and are completely 
lost. This takes place three days before the huntress emerges from 
her cocoon. The supports are inflated with a watery fluid which 
disappears as soon as a breach occurs in the pupal skin. One may be 
cut off without seriously injuring the wasp, but the removal of all 
causes deformed legs owing to the abdomen sagging upon them. 



76 INSECT BEHAVIOR 

Emergence from the cell as a perfect insect takes place twenty- 
one days after pupation. If the parent wasp lived she might witness 
the home building of her children, thirty-eight days after she de- 
posited them as eggs in cells of her own workmanship. 




A cabbage butterfly depositing an egg 

This common white insect is responsible for enormous annual loss, its offspring destroying great quantities of 

cabbage throughout the summer months. Like many of our pests it is an introduced species 



LL 




^ 













. * :'ijf*^^' ^. > 



♦*\ ••4 



:4.-^-*'*- 










Fortunately the cabbage butterfly's ottspring are liekl in check to some extent by pa|Hi-\\ asps. 1 heir chief 
enemy, however, is a tiny Ichneumon fly whicli deposits its eggs in tlie cabbage caterpiUar. Later its young 
burrow out through the skin of their host, spinning small cocoons about the dying and depleted caterpillar. 



CHAPTER IX 

CONTROLLED PUPATION 

THERE is a tree in the Guiana forest which, for lack of a 
better name, I call the vermilion-nut This tree ranks high 
in the scale of giants. It towers above one, reaching more 
than a hundred feet above the forest floor, where it throws 
out its rather flattened boughs that bear a thick mass of foliage, and 
in April, a vermilion fruit. This fruit is lime-shaped, two inches 
in length by one and one-quarter inches wide, and consists of a moder- 
ately tough pubescent vermilion shell, guarding the soft, greenish 
inner pulp that surrounds the true nut. The pulp is soft and quite 
sweet, but incipient, and the nut is as hard as a fresh almond and 
slightly over twice as large. Even to botanists its name is unknown. 
Troups of howling-monkeys make daily visits to these trees, gorg- 
ing themselves for hours on the juicy pulp and throwing the shells, 
bearing their teeth marks, to the ground below. One must either lie 
upon the back or suffer a cramped neck to observe them feeding in 
the top-most branches. Even then they are often screened from one's 
sight by the masses of heavy foliage that characterize the vermilion- 
nut. 

Other animals find the food to their liking also. Agouti, smaller 
species of monkeys, and a host of wild bees feed daily beneath the 
everlasting twilight of these branches. One might spend a year 
studying the creatures that feed upon the fruit, which is often scat- 
tered abundantly among the rotting vegetation on the ground for a 
hundred feet in every direction. 

In the latter part of April, I came upon a band of howlers feast- 

77 



78 INSECT BEHAVIOR 

ing in one of these trees. They were easily one hundred and twenty- 
five feet from the ground, yet quite unconscious of the dizzy height, 
they reached here and there for the fruit, seldom clinging to the 
branches with other than the hind legs. They ate with great relish 
and greed, plucking far more than they could possibly eat. Conse- 
quently many nuts were dropped quite untouched, and wasted. 
Curious as to the quality of the fruit, I picked one up and split it 
apart. To my surprise it contained eleven light yellow maggots, that 
writhed about actively and tried to escape from their late prison. 
They had eaten the soft pulp entirely away, leaving only a mass of 
brown excreta and the inner nut, which was free and rattled about 
when I replaced the shell which had been cut away. Thus, by chance, 
I discovered the subject of this chapter in its strange cradle among 
the tree-tops, where it has doubtless fed in its larval state since the 
first vermilion-nut blossomed in the branches of its parent. This is 
a new species of fly belonging to the family Trepetidae, and the genus 
Spilographa. 

When and how the mature insect deposits her egg within the nut 
is beyond me. It would be necessary to live in the loftiest branches 
to ascertain such a fact. One glance at a vermilion-nut tree would 
stand as evidence of its infeasibility. One thing we do know; the 
insect is a fly, as shown by the larva, a typical fly maggot, with eleven 
segments, counting the head. It tapers from a well-rounded segment 
at the posterior end, almost to a point at the head, which is supplied 
with two hooks turned downwards like the claws of a cat. It is trans- 
parent yellowish white and through its entire body one may trace a 
pair of respiratory tubes with one set of openings in the head and 
the other in the last segment of the body. These orifices, two in front, 
two behind, stamp the creature as a young or larval fly. 

The eggs are probably deposited when the fruit is still soft and 
immature or perhaps the scent of the tree's blossoms beckons to the 



CONTROLLED PUPATION 79 

insect. I can but surmise. Later the eggs give place to tiny wiggling 
larvae, whose movements depend upon contractions of their muscles, 
for they are devoid of feet. They feast like gluttons upon the nascent 
flesh of the ripening fruit until it comes time to pupate. 

From what we know of many other flies, we have seen that it is 
natural for them to pupate within the ground, or at least in a position 
from which they may work their way to the light of day when nature 
has transformed them into perfect insects. The larval flesh fly bur- 
rows below her carrion to transform in the damp soil beneath, the 
house fly in its bed of manure finds escape an easy matter, the mosquito 
transforms in the water, but what of our flies born within a tough- 
shelled nut in the highest forest branches? How are they to release 
themselves from such a prison after the feast is over? As we have seen, 
they reach the ground by falling, when the nut is plucked by some 
roaming monkey, or as it falls anyway when ripe, carrying its living 
burden earthward. But that is not answering the question. The 
larvae must burrow into the forest soil to transform and issue suc- 
cessfully as a perfect insect. How, then, is this feast accomplished? 

The nut which I cut open contained eleven larvae. They appeared 
to be full grown and ready to pupate, at any rate, there was no more 
pulp left for them, and if they were hungry they must eat again 
that which had been digested once. No, they simply wiggled about 
frantically as though searching for an opening and swarmed to the 
hole I had cut. 

I remove two of them to tubes of soil slightly dampened. The 
remainder are locked once more in their prison. In the tubes con- 
ditions are, as nearly as I can make them, like those of the forest floor. 
The larvae move here and there from fright in their new environ- 
ment for a minute or two, but presently one thrusts its pointed head 
into the soil and commences to burrow. Soon it is followed by the 



8o INSECT BEHAVIOR 

other larvae in their respective tubes. In twenty minutes all have 
disappeared below the surface. 

Two days later I remove the material from the tubes in search of 
the larvae. They have burrowed slightly over half an inch below the 
surface and all have transformed into little yellow kegs with ten red 
hoops running around them. Under the lens these hoops appear to 
be tiny bands of stitches like those in the cover of a baseball. In 
these pupae we have convincing evidence that our fly naturally trans- 
forms below the ground, especially so in view of the fact that the 
larvae left within the nut are still strictly larvae in every sense of the 
word. 

I remove two more of the imprisoned ones from the nut to freshly 
prepared tubes of earth. Two days later I have the same result from 
my experiment. Those within the tubes have transformed to pupae, 
but those still imprisoned in the vermilion-nut remain in the maggot 
form. I keep the prisoners in their cell from April 20th until the 
1 2th of May. Still there is no change from the larval form, yet any 
day I remove one to a tube of earth and forty-eight hours later re- 
cover it as a pupa! It is a strange condition indeed, but I think I 
see its significance. 

When I open the fruit on the tenth day of May, I note that the 
true nut within has sprouted ever so slightly. Each day the cotyledons 
of the new tree are swelling within the shell that holds them, push- 
ing upwards in response to the light above. Were the nut lying nat- 
urally upon the moist floor of the forest, the young tree's progress 
would be even faster. At length the pressure becomes too great for 
the nut's outer shell to bear. It yields to the vortex of a new life, 
splits open, and at the same time the imprisoned larvae find the long- 
waited-for exit to the friendly mould of the forest. 

Here is a condition among insects previously unknown to me. It 
is a remarkable adaptation to the condition of the creature's strange 




Male and female paper-wasps hatching from the cells of a nest, in July. Enlarged four times 




Paper-wasp worker with unusually large pellet of wood-pulp preparing to enlarge the nest. Enlarged four times 



CONTROLLED PUPATION 8i 

habitat, that has brought about a deviation from the rule. In short, 
the young flies may hasten or postpone pupation at will! I would 
have hesitated to set forth such a statement, even as a remote possi- 
bility, were it not for my experiments that cannot be denied. One 
learns to expect the unexpected in nature, but who would go so far 
as to accuse her of running even so tiny a creature as this nascent 
fly, without a schedule? She is forced to surrender here to conditions 
self-imposed. If her children within the vermilion-nut lie impris- 
oned without food for a fortnight or more, it matters not. When re- 
lease comes they are none the worse for their experience. If they 
are spilled roughly on the ground from a freshly broken nut a month 
before their brothers, so much the better. They have no set time for 
pupation. They will become flies just the same. Thus Nature has 
endowed them with ability to meet successfully, the strange circum- 
stances in which she herself has placed them. 

Let us see what has happened to the larva that has burrowed be- 
neath the surface of the ground. Why must such an active creature 
entomb itself again upon being liberated from its original prison? 

Unlike ourselves, animals or birds, insects pass through a series of 
stages, one might say, almost by jumps. At first we have an egg, quite 
helpless, but deposited with due care and forethought by its provident 
bearer. In a day or so, this helpless egg has become a ten-ringed 
maggot with a head, appendages for drawing in its food and possessed 
of a primitive but efficient set of organs. It is not an actual hatching 
as we see it in a hen's egg that has brought this strange creature into 
the world, but a fading of egg into maggot. There is no empty shell 
when the process is finished, no specter of the creature's former self. 
The process is like that of a moving picture, which fades before one's 
eyes from one scene to the next, which is widely different. 

In its newly acquired form, the insect feeds, as we have seen, upon 
the vermilion-nut pulp, remaining unchanged except in size, until 



82 INSECT BEHAVIOR 

fate releases it upon the moist forest floor, when with a haste that is 
almost frantic it immediately imprisons itself once more, this time 
in the ground wherever it chances to find itself. Forty-eight hours 
later, we discover it as a tiny yellow keg, banded with red stitches, 
as though it had buried itself for good in a self-fashioned coffin. 

Has the insect become so accustomed to the blackness of prison life 
that it cannot live in a world of sunlight? Must it live the life of a 
mole because it has only once seen the brightness of day? No, there 
is a far deeper reason than these, that sends it so hastily into the 
ground. It is about to undergo its last and greatest transformation, 
one during which it will be once more utterly helpless against the 
slightest odds. It must lie very still, as though in death, lest the 
beautiful process within be interrupted and the design shattered. 

Up to now, the insect has resembled its ancestral family, less highly 
developed worm-like creatures of another day. Just as we have de- 
veloped from less perfect creatures, so has the fly. Within the 
little yellow keg a wonderful change is in process. 

At first the maggot, so recently an active definite creature, is seized 
upon by a host of nature's strangest forces. We cannot see them or 
give them any definite form. Nevertheless they are there, like a 
great group of wreckers, carpenters, masons, painters and decorators. 
The larva or maggot, the ancestral form, is torn down and reduced 
to a disintegrated mass of fluid. From this utter wreck of what was 
so lately a crawling, organized creature, the final insect is resur- 
rected. From old tissues, new ones spring, from what was old and 
out of date, a more modern creature is erected. The yellow keg is no 
longer a coffin, but a factory wherein a host of raw materials are 
to be transformed into the finished product! 

The process is comparable to tearing down an old-fashioned house 
and erecting a modern one on the old foundations. Much of the 
old material is used, and that which must be replaced by new, is 



CONTROLLED PUPATION 83 

burned or otherwise disposed of. So it is with the tissues of the 
maggot. From the old house we save the plumbing, the wiring and 
the kitchen range, which corresponds in the maggot to the repro- 
ductive glands, the nervous system and the heart, which are left in- 
tact, or at most altered and attended to. 

At length it becomes time for the painters and decorators. Nature 
employs a vast army of these. In the keg, after ten days, the milky 
white and partly transparent, but otherwise perfect insect commences 
to receive its color. It appears first in the eyes with an influx of 
emerald green pigment studded with golden, microscopical dots, 
which are followed in forty-eight hours by the appearance of black 
patterns upon the legs and wings, due to more or less dense hairs 
upon these appendages into which the color gradually flows. Upon 
the back of the head there is a pattern of hairs and another of longer 
ones upon the thorax, while the abdomen likewise suddenly appears 
clouded with pubescence. Further than this no ground color or 
markings can be seen, owing to the color being much like the shell 
of the keg itself. 

In another forty-eight hours, fourteen days after pupation, the fly 
emerges by splitting the head of the pupal keg in two equal parts. 
This is a simple operation, as the shell is not too substantial, but 
the new-born fly has yet another task, before it will be free. It has 
yet to dig a passage from its tomb to the light of day. It must be 
done quickly, lest the wings fill and dry too small and their use- 
fulness be lost. 

For this purpose the insect is supplied with a battering ram, which 
protrudes between the eyes at birth from the pupal case. It is a trans- 
parent sack-like appendage which may be expanded or contracted 
at will by the fly. It contains no apparatus of any kind, but is ap- 
parently the forehead of the insect capable of expansion. To watch 
the operation of this strange appendage is remarkable. First, it 



84 INSECT BEHAVIOR 

swells like a toy balloon when air is blown into it, until it protrudes 
two or more millimeters in front of the insect's head, pushing the 
sand or dirt in front of it as it increases. This is followed by a 
rapid deflation of the ram, which leaves an indentation into which 
the fly struggles with great effort. Now the first operation is re- 
peated, the second indentation made and again the insect wedges it- 
self into it. Thus, after an hour, if the fly is fortunate, it reaches the 
surface of the ground, where it rests for a time to recover its strength, 
before launching into a new and sunlit world once more to search out 
the vermilion-nut, this time as a nursery for its own offspring. 





— . c 






\. * ^^. n ■' y *-^ "v 




"^^ Ju.^^^ ^ ■**!' -*. 



CHAPTER X 

CANNIBAL WASPS 

Philanthus gibbosus 

IN the glaring July sun, seething in a dizzy sea of rising heat 
waves, the cannibal wasps have built their city. The tennis 
court, but let us forget the human world, in the eyes of the in- 
sects, is a great sandy plateau, dotted in a hundred places, with 
tiny hills of sand that mark the excavations of their metropolis. 

It is a barren land where mud huts bleach in a sun that knows no 
mercy and yet strangely enough, where the lives of its inhabitants are 
filled with endless work and gigantic energy. 

If you can imagine a tropical climate without trees and where the 
creatures that people it possess greater energy than those of a temper- 
ate zone, then you will have a fair idea of the conditions existing in 
the topsy-turvy land of the cannibal wasp. 

The insects are gregarious, but a separate burrow, or mine, is con- 
structed by each female belonging to the general colony. 

These tunnels are the homes of the wasps, mines in which the 
domestic duties are carried on. They are excavated in various 
fashions, twisting and turning according to the conditions of the 
ground. In all, the burrows may reach twenty-four inches in length, 
terminating in an elongated cell or chamber, twice the width of 
the passage leading to it. One or two short branches, also terminating 
into roomy chambers, may be found at various points near the end 
of the shaft. These cells are nurseries where the young wasps 

are reared and of which we will hear more later. 

85 



86 INSECT BEHAVIOR 

Beside the entrance hole to the burrow, a second tunnel, about two 
inches in length, is sometimes excavated, which serves as a sentry 
box, in which the insect rests and guards the entrance to the main 
nest. It is amusing to see a wasp from the colony lose its bearings 
and attempt to enter the wrong nest, when the rightful owner rushes 
from her sentry box and pounces upon the intruder. Then amid 
loud buzzings, which are doubtless oaths of a fearful nature, the two 
roll about until the intruder is driven off. 

But let us go back to the building of the burrow, which is a gigantic 
task for so small a creature. She must be engineer, laborer, drill and 
steam shovel if her race is to survive, and this is no small burden for 
such delicate shoulders to bear. 

But in a wasp city there is never a complaint, never a strike for 
higher wages, but always a superb spirit of altruism and a wealth of 
strength that defends the race against extinction. In a way, instinct 
triumphs over intelligence here. 

At the entrance, one finds a heap of dirt excavated from the bur- 
row, which is carefully piled, in order that it will not run back 
into the doorway and double the labor of the well-planned dwelling. 

On arriving at her tunnel, the miner alights at the far edge of the 
sand heap. From here she moves rapidly forward, kicking the sand 
back the while, thus forming a distinct trough leading to the hole. 
This clever method of approach is to prevent sand from rolling into 
the nest, which would be the case should she come blustering directly 
into the entrance. 

To compare the weight of the sand heap with that of the wasp 
will be interesting. For this purpose the diggings from an average 
tunnel are scooped up and placed upon a delicate scale. It registers 
about two ounces. Now we place the wasp on the scales and find 
that its weight in the same measure, is one four-hundredth part of one 
ounce. 








'S..,~4 tt^:3f<f 



— ^j« ; " ' 



'^l^-J 



*» J*! - » 



f'J^J' ' 



The cannibal and her diggings. In excavating her tunnel, the insect removes her weight in 
sand eight hundred times. Life size. From a mounted specimen. 




A complete model of a cannibal wasp's burrow. This model, secured by pouring molten 
lead into a nest, clearly illustrates the shape of the tunnel with its extra tube or sentry 
box at the left. One-third natural size. 



CANNIBAL WASPS 87 

In other words, the wasp in excavating, has removed her weight 
in sand eight hundred times. Now let us compare her work in pro- 
portion with that which a man would have to do to accomplish a 
similar feat. Taking a man weighing one hundred and fifty pounds 
and multiplying by eight hundred, which are the same figures used 
in the case of the wasp, we get one hundred and twenty thousand 
pounds, or sixty tons. The insect then removes the equivalent of 
sixty tons of earth to make her nest. This she does with no tools 
except her forelegs, and the gigantic task is completed in four days. 
Had we- the same strength and endurance, the Panama Canal might 
have been completed in a week or two I 

When the excavation is finished, the insect at once turns her atten- 
tion to storing the subterranean cells with proper food for her off- 
spring, and here we shall bring to light the cannibalistic instincts of 
these mining wasps. 

The majority of the solitary wasps feed their young upon inch- 
worms, spiders, flies, or insects of an entirely different order from 
themselves. But not so the miners; who in some cases deliberately 
hunt out members of their own family, paralyzing them with a drive 
of the sting and dragging them into the tunnels for their young to 
feast upon! 

As many as a half-dozen victims may be packed into a single cell. 
Tiny humble bees, green and blue flower bees,^ and sometimes unfor- 
tunate miners that have been executed for daring to place a foot in 
the wrong doorway. 

In a week the cells are packed from end to end with victims of the 
cannibal's pitiless nature. The array is more gruesome than the 
corpses lying in a morgue, yet the insect gloats over her industry of 
murder, rushing eagerly in to inspect the contents of the cell, over 

'^ Ceratinadae. 



88 INSECT BEHAVIOR 

and over, before laying her glistening oily yellow egg upon the mass 
of helpless flesh. 

In two days the young cannibals wriggle from the eggs, footless, 
whitish maggots and helpless against the slightest odds. Yet nature 
has provided for them in such a manner that they may attach them- 
selves to superior creatures, who must lie motionless and submit to 
their suckling mouths until the last cells of life pass into the bodies 
of the cannibals 1 

A single egg is laid upon the contents of each cell, and normally 
seven days are required by the young to gorge themselves into a state 
of torpor which lasts until the following spring. Then a wonderful 
transformation takes place. The motionless, fatty larva commences 
to assume a definite form. 

Within its milky skin, disintegrated tissues and layers of cells have 
been whirled by nature's magic hand into definite parts and organs 
of the nascent creature. Legs unfold like budding leaves, a narrow- 
ing of the waist separates the thorax from the abdomen and delicate 
wings "sprout" from the center of the back. 

Then comes color, darkening the head and thorax and throwing 
yellow bands about the abdomen, and finally comes the gift of motion, 
which leaves only a layer of earth between the cannibal, the sun- 
light and another generation of innocents to become her victims. 

Grimes cannot always go unpunished. There must be justice, even 
in the insect world. This slaughter of the innocent flower bees must 
be avenged or regulated and nature's reprisal is cunning and severe. 

There is another wasp-like creature, a true fly in reality, that plays 
her part in this gruesome drama. Nature has given her a flight that 
resembles a wasp's, to afford protection from minor enen^ies, but this 
is not the most remarkable of her gifts. It is her mission in life to 
hold these cannibals of the insect world in check, and she performs 
her duty with precision. 




A wasp of the sphecid's size compared to a small rove beetle. Although four times life size in the picture, 
this insect is a formidable creature in its natural size. Note the tongs upon the legs which in the sphecid 
assist in carrying the prey. 




'^ 



y- 



I 










Sphecid wasp dragging a paralyzed cicada to her 
burrow, after the iiomeward flight. 



Common cicada, upon which the splucul wasp 
preys. 



CANNIBAL WASPS 89 

While the cannibal is abroad in search of a victim, this creature, 
which we will call the checker-fly,^ because of the peculiar pattern 
upon her abdomen, takes her life in her hands and slips into the 
den of the murderer. 

Now to understand this action we must first examine a checker- 
fly in the laboratory. Dissection brings a wonderful fact to light. 
In the fly's abdomen we find no eggs, as one might expect, but in their 
place ten living larvae! The microscope shows them to be whitish 
maggots clustered together in a ring, and through their transparent 
bodies one may see the expanding and contracting of embryonic 
muscles. 

The checker-fly then gives birth to her young alive! But why? 
She is a lowly rung in the ladder of insect life, while the cannibal, 
a member of the highest order of insects, is gifted with nothing more 
unusual than egg laying! 

The explanation is simple. When the checker-fly enters the bur- 
row, she heads straight for the cell, in order to bear her young upon 
the meat stored up by the wasp for her own offspring. Thus she 
saves herself the trouble of providing a home and food for them. 

We must know that the wasp is nearly four times as large as the 
fly and greatly superior in strength. Now should the fly and the wasp 
both lay eggs, the ultimate result would be at once apparent. 

The eggs of both insects would hatch about the same time, but 
the young cannibals would soon grow much larger than the flylets. 
The strongest individuals survive, and were it not for nature's care 
in such matters, the young checker-flies would perish. 

What takes place is plain. The parent fly bears her young alive 
and they start at once feeding and growing within the cell. In two 
days the wasp's eggs hatch, but the young checker-flies have now 

^ A species of Tachininae. This sub-family includes some of the most highly 
beneficial species of flies, such as the Red-tailed Tachina (Winthemia 4-pustulata), 
a parasite of the Army worm. 



90 INSECT BEHAVIOR 

gained sufficient strength and size to push aside and starve the new- 
born wasps! 

Thus nature modifies the birth rate of the cannibals, sending these 
checkered enemies to destroy them, lest some day they exterminate 
the useful little flower and humble bees, whose mission in life it is 
to blend the pollens of a billion blossoms and make our world a 
land of plenty. 




Comparative wing expanse of cicada (left) and sphecid wasp (right) 











'ff irrlr^ r JM «^*"^2v*i' i 4 



Hole in cicada tliroiitil\ which the larval spiiccid 
entered its host 



^"ouni; sphecid wasp two days old tcodmg upon a 
paralyzed cicada 



CHAPTER XI 

THE SPHECID'S DUTY 

Sphecius speciosus 

WHEN July has blended its last hot days into August 
and 'the lair vibrates with the nionotonous, irritating 
song of the cicada, it is then that one member of the in- 
sect world, the great golden digger, is hardest at work. 
Though the most formidable member of our eastern American wasps, 
being the largest, and possessed of a most powerful sting, it is perhaps 
more peaceable and less easily irritated than many of the smaller 
members of the Hymenoptera family. 

Solitary wasps, of which the golden digger is one, are invariably 
more peaceful and easier to work with than social species, for a very 
simple reason. Solitary individuals are almost all preying species, 
creatures who require the services of their stings in paralyzing their 
victims. They reserve their poison and the energy required in in- 
jecting it, until it is time to gather provender for the coming genera- 
tion of their kind. Such wasps sting in self protection only when 
captured, and scarcely ever in defense of their nests. 

Social wasps and bees seldom, if ever, sting their prey and many 
of them are not even of predatory habits. The sting is therefore un- 
necessary in capturing or preparing food for their offspring and is 
used, as we know, chiefly in defense of the nest, which is the common 
property of a number of individuals. 

The sphecid's service to mankind in killing countless numbers of 
the noxious cicadas makes this great wasp a popular one with those, 

all too few, who understand its highly beneficial function. 

91 



92 INSECT BEHAVIOR 

As in all insects, the wasp's first vital duty upon leaving its cocoon 
is to mate and deposit her eggs, which in due time are to bring forth 
the diggers of the following season. Her life story is most interesting. 

Towards the middle of the day, when the cicadas are singing in 
every tree, the sphecid may be seen flying swiftly to a spot from 
whence a song is issuing. For a minute she disappears among the 
foliage, then suddenly the song ceases abruptly, giving place to a 
cry of agony and fright. The wasp has seized the unsuspecting 
cicada, and its terrible sting has been driven in, instantly paralyzing 
and throwing the unfortunate insect into a comatose condition, from 
which it never recovers. 

The wasp and cicada will often fall to the ground together, 
struggling violently, the ill-fated bug giving vent to discordant death 
cries. From here the wasp carries its burden to the nest, which is 
often a difficult object to accomplish. The cicada is heavier than 
the wasp herself, which is a condition rarely met with among the 
preying Hymenoptera, and to carry the victim to the burrow often 
requires much time and patience on the part of the sphecid. 

If the wasp and cicada fall from the foliage of a tall tree, all goes 
well. The wasp recovers before reaching the earth and flies to the 
nest without difficulty. Usually, however, the two strike the ground 
in a noisy struggle, where the sphecid accomplishes her work of 
paralyzing the cicada, often in a tiny cloud of dust. When this 
happens the wasp cannot lift her dead weight victim into the air. 
Try as she may, the precious meat will not budge from the earth and 
one wonders how the journey to the nest will be accomplished. 

It has been stated that in such a case, the wasp drags the cicada 
overland, but this I have found to be untrue. The sphecid's course is 
very simple and interesting. 

She drags her burden to the nearest tree, mounts to a distance 
of twenty feet or more and from this lofty perch launches herself 




Queen paper-wasp in the act of depositing an egg which may be seen just emerging from the insect's body 

Enlarged seven times 




a 



THE SPHECID'S DUTY 93 

into the air with the cicada, which is now quiet and helpless. At first 
she tumbles like a wounded aeroplane, but at length recovers, rights 
herself and thus gains sufficient momentum to fly without halt to 
the nest. 

The nest consists of a sloping burrow, continuing under the ground 
for about eight inches in a straight line. A sharp turn is usually made 
at this point and the tunnel carried on for twelve inches more. At 
the extreme end there is an elongated cell, large enough to hold a 
single cicada. Branches from the main passage are often excavated, 
and occasionally one of the cells at the ends of these branches will 
contain two cicadas. It has been stated that these cells containing 
two victims bring forth much larger wasps than those containing one, 
and as the female wasp is much larger than the male, it was thought 
by a well-known entomologist that the cells containing the greater 
amount of provisions produced the females and those containing a 
lesser amount, the males. However, it does not seem probable that 
an insect possesses the power of distinguishing her eggs to the extent 
of telling which are to bring forth the males and which the females. 

When a cell contains its store of cicada meat, a single whitish egg 
is laid under the middle leg of the victim. After this the burrow is 
closed up by the wasp and her duties are finished. The eggs hatch 
in two days, and the larvae, as the young grub-like sphecids are called, 
start at once to suck the nourishment from the bodies of the cicadas, 
later entering the hosts' bodies, where they attain full size in seven 
or eight days. 

Now a rough cocoon is spun by each inside of its respective cicada, 
wherein it later transforms to a pupa, the stage corresponding to the 
chrysalis of a butterfly. 

In this soft, helpless condition it remains all through the winter, 
until the following summer.. Then, when the cicadas are calling 
once more, the long buried cocoon, from which the hollow shell of 



94 INSECT BEHAVIOR 

host has long since rotted away, splits open. Out crawls the powerful 
giant wasp, she brushes herself thoroughly and waits for strength to 
dig her way out. 

In a few hours she has made her way laboriously to the surface of 
the ground. Here, all laden with mud and the sweat of her efifort, 
she cleans and scrubs and rubs the dirt from her limbs. She draws 
her feet through her mouth and with this droll fluid polishes her 
eyes. Last, she scrapes her feelers clean, curls them back and forth, 
spits upon them, rubs them until they shine like metal. Having thus 
made her toilet, she is off, expert of wing at her virgin flight. She 
goes in a straight line out of sight, in search of a male to become her 
mate. 




Cells of a paper-wasp's nest, showing heads of young insects, and silken caps spun at a later date. Four times 

life size 




Unlike the large globular nests of the hornets, those of the paper-wasp's are simply masses of uncovered cells. 

Life size 



CHAPTER XII 

THE ORIGINAL PAPER-MAKERS 

THE societies of the paper wasps,^ like those of other social 
insects of the family, consist of three kinds of individuals, 
males, females and workers. The colonies only exist for a 
single season, the males and workers dying in the fall. The 
females or queens hibernate and each starts a new community in the 
spring. The queen is the largest in the colony and her one duty, 
after the first few weeks of spring, is egg laying. The males or 
drones are created for the one purpose of fertilizing the eggs of the 
queen and after performing this duty they are frequently killed and 
thrown from the nest by the workers. These so-called workers are, 
in reality, undeveloped females, who are unable to reproduce in a 
beneficial way, as their eggs invariably produce drones. Thus they 
are unable to assist in increasing the numbers of working individuals 
in the colony and the heavier work must therefore fall upon these 
otherwise useless members. 

Let us start with the queen mother, the only survivor of last year's 
colony, who has safely passed through the winter in an impregnated 
and torpid condition and who must now lay the foundations of another 
great insect city. 

When in the spring she lays the foundations of her future empire, 
she has not a single worker at her disposal, and with her own hands 
and teeth she must lay the corner-stone of her future metropolis. 
She must herself build the first combs and produce from her own 
womb their first inhabitants, which in their infant state, she must feed 
and educate before they can assist her in the great design. At length, 

^ Polistes pallipes. 

95 



96 INSECT BEHAVIOR 

she receives the reward for her perseverance and labor; and from 
being a solitary unconnected individual, in the summer is enabled to 
rival the queen, who gave her birth, in the number of her children 
and subjects, and in the empire of which they are inhabitants. Even 
at this time, when she has so numerous an army of helpers, the in- 
dustry of this creature does not cease, but she continues to set an 
example of diligence to the rest of the colony. If in any way the 
queen mother perishes, before the other females are hatched, the 
workers lose their instincts, cease their labors and die. 

The number of females in a paper wasp colony is quite consider- 
able. They are hatched about the latter part of July or during the 
first part of August, at the same time and in about the same numbers 
as the males. In September and October, they fly from the nest 
and after mating, the males live but a short time. Of all the females, 
very few survive the winter to start the new empires when the vernal 
sun brings the insect world to life again. 

To the workers falls the entire care of the young and other members 
of the colony. They must not only supply the food, which consists 
of honey and chewed-up insects, but they must also protect the nest 
from outside intruders. These neuters must be ready and willing at 
all times to do reconstruction work upon the rapidly growing nest. 
Almost daily there are new cells to be built, walls to be strengthened, 
openings to be closed and all manner of things which it is only proper 
for a worker to do. Of all these operations no other is so interesting 
as the process by which the wasp's paper is made. It is manufactured 
of wood pulp or other ligneous fiber, which is scraped by the worker 
from old weathered boards, fence rails and other unpainted wood 
which has weathered for a number of years. I once found a pole 
which supported a bird house, so thoroughly scraped by paper wasps 
and so frequently visited by them that it was kept in a roughened 
condition all summer. This pole must have supplied the pulp for 




Cells of the paper-wasp with caps removed to show heads of pupae nearly ready to emerge as perfect insects. 

Greatly enlarged 



THE ORIGINAL PAPER-MAKERS 97 

many nests in the neighborhood, and even now is used year after year 
by insects of this family. 

The tiny particles of wood fiber are mixed by the wasp with a 
glutinous substance, which is apparently secreted by the worker her- 
self. She rolls the whole mass between her forefeet and masticates 
it with her mandibles, until a small gray pellet has been formed, and 
with this she flies to the nest. The pellet is then dropped in the 
proper place and left until a portion of it adheres to the edge of the 
cell in course of construction. When this has been accomplished, the 
insect draws the pulp from a ball or pellet, into a long thin line, to the 
opposite side of the nest. From here she returns to the starting point 
and, placing her tong-like jaws over the paper thread, closes them 
and simply walks slowly backwards away from the point of contact, 
thus flattening it out into a long gray ribbon, which is easily shaped 
in the form of a low hexagonal cell. 

In this manner several layers of paper ribbon are applied, each 
layer above the other, until the cell is of proper depth. It is then 
ready for the delicate white egg which the queen lays, almost at its 
very bottom. The egg is fastened to the paper wall by a glutinous 
substance, which is probably the same secretion that is used in making 
the paper, and it is almost impossible to remove it, without leaving 
a portion of its tender shell adhering to the inner wall of the cell. 

In the course of a few days the eggs hatch out into soft footless 
maggots, like all young Hymenoptera, and it is at this period of their 
lives that they are subject to the attacks of a very curious beetle para- 
site, known as the Xenos. The young of this insect is a tiny active 
creature which burrows into the body of the young wasp. There it 
lives, feeding upon the body of its host during its hypermetamorpho- 
sis. If it is to be a male, it transforms into a chrysalis and soon after 
this hatches out from the body of the wasp to live its short adult life, 
which lasts from fifteen minutes to three days. If a female, however. 



98 INSECT BEHAVIOR 

it never reaches the chrysalis state, but when the maggot host itself 
changes into one, the apparently immature Xenos pushes one end of 
its body out between two of the host's abdominal segments and there 
gives birth alive to a great many tiny beetles, in the earliest and most 
undeveloped stage of their lives. 

Owing to the position of the comb, when the young wasp emerges 
from its egg, it is suspended head downwards in the cell. It is, how- 
ever, attached to the cell at its posterior end and remains so until 
full grown and ready to spin its cocoon. At this period it becomes 
detached but the bottom of the silken cocoon, which has now been 
spun, forms a capstone to the previously open cell and prevents the 
youngster from tumbling out. In this position the young wasp trans- 
forms to the pupal state, in which it remains for some time before 
issuing as a perfect insect to take up the work of the colony. 

After this event the cell is thoroughly cleaned out by the workers 
and used over again by the queen. The entire period from the time 
that the egg is laid until the full grown wasp issues from its cocoon, 
is about five weeks; thus it will be seen that the same cells may be 
used several times during a single season. 

The last brood of the year consists mostly of queens and drones 
and after these have been hatched the workers of the colony soon 
die. The inside of the cells may then be found to contain curious 
brownish skins, cast off by the chrysalids and which the workers did 
not have time to remove before the cold weather arrived. 

Unlike the large globular nests of the hornets, those of the paper 
wasps are simply a mass of uncovered cells, ranging in numbers from 
fifty to three hundred. These are suspended by a single central stem 
from the undersides of large overhanging stones or from beams in 
old barns and sheds. 

These insects are undoubtedly beneficial from the fact that they 




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THE ORIGINAL PAPER-MAKERS . 99 

have been known to prey upon the destructive cabbage caterpillar ^ 
in the vicinity of Washington and also in Connecticut. Howard, in 
his "Insect Book," describes their actions as follows: "The wasps 
would hover above a plant and then alight and walk about it, but 
finding nothing, would continue to the next plant, and so on to the 
next. In the sunny center part of the field the cabbage caterpillars 
were exterminated, but in the shady portions next to a patch of woods, 
they were present in great numbers. Wasps do not see small objects 
clearly. They find their prey more by sense of touch than by sense 
of sight, and as they prefer the sunshine they unconsciously ignored 
the abundant caterpillars in the shade." 

Kirby has left us the following extraordinary account of the manner 
in which the workers care for the young and helpless members of the 
community. These observations apply to the common yellow jacket 
or hornet, but many of the statements hold true in the case of the 
paper wasps, although I have not as yet been able to verify them all. 
"The workers are the most numerous, and to us the only troublesome 
part of the colony, upon whom devolves the main business of the nest. 
In the summer and autumnal months, they go forth by myriads into 
the neighboring country to collect provisions; and on their return to 
the common den, after reserving a sufficiency for the nutriment of the 
young brood, they divide the spoil with great impartiality; part 
being given to the females, part to the males and part to those workers 
that have been engaged in extending and fortifying the community. 
This division is voluntarily made, without the slightest symptom of 
compulsion. Several wasps assemble around each of the returning 
workers, and receive their respective portions. It is curious and in- 
teresting to observe their actions upon this occasion. As soon as a 
wasp that has been filling itself with the juice of fruits, arrives at the 
nest, it perches upon the top, and upon disgorging a drop of its sac- 

^ Pontius rapae. 



100 INSECT BEHAVIOR 

charine fluid, is attended sometimes by two at once, who share the 
treasure. The first drop being thus distributed, a second and some-, 
times a third is produced, which falls to the lot of the others. 

"Wasps do not, as a rule, store up honey, but it is found in the cells 
of some European species as well as in those of America. 

"Another principal enjoyment of the workers is enlarging and re- 
pairing the nest. They work with great celerity; and though a large 
number are occupied at the same time, there is not the slightest con- 
fusion. Each individual has its portion of work assigned to it, ex- 
tending from an inch to an inch and a half, and is furnished with a 
ball of ligneous fiber, scraped by its powerful jaws from posts, rails 
and the like. The workers also clean the cells and prepare them to 
receive another egg, after the first has passed through all the stages 
of its life and is now a perfect insect working with the rest." 

There is good reason for thinking that wasps have sentinels placed 
at the entrances of their nests, which, if you can seize and destroy, 
the remainder will not attack you. This has been confirmed by the 
author. If a nest of wasps be approached without alarming the in- 
habitants, and all communication be suddenly cut off between those 
out of the nest, and those within it, no provocation will induce the 
former to defend it for themselves, but if one escapes from within, 
it comes with a very different temper and appears commissioned to 
avenge public wrongs. In fact, very few incoming bees or wasps 
will attack the intruder. Perhaps it is because the insect who is re- 
turning to the nest sees what is going on about its home, while the 
one coming from inside the nest is confronted suddenly by an unusual 
form when it reaches its usual point of exit. It becomes alarmed 
not only for itself but for the safety of its colony. What follows is 
only too well known to the student of such insects. When the workers 
make their rush they are prepared to sacrifice their live§ in the 
execution of their orders. 



THE ORIGINAL PAPER-MAKERS loi 

The first cold weather, after the queens have entered their winter 
quarters, produces an effect upon them similar to that which is pro- 
duced upon the woodchuck and other animals subject to torpor. At 
first a partial benumbment takes place, but the insect, if touched, is 
still capable of moving its organs. As the cold increases, all the 
animal functions cease. The insect breathes no longer and has no need 
of a supply of air; its nutritive secretions cease, no more food is re- 
quired, and it has all the external symptoms of death. 

Thus we will leave the few survivors of a once great insect empire, 
perhaps huddled behind the picture moulding in our bed-room, in- 
significant now to be sure, but planning perhaps in their insect heads, 
every cell, every gallery, and every passage which is to be built when 
the new colonies are founded in the first warm days of April. 



CHAPTER XIII 

INSECT AND OTHER STRATEGISTS 

INSECTS, like all other creatures of this earth, from sponges to 
man, must partake of food, for without it there would be no life. 
It is a simple thing to say, but for some insects of the lower 
orders, to procure their proper nourishing food would be quite 
a different affair, were they not carefully assisted by that almost in- 
tangible thing called instinct, taught in the school of nature. To be 
sure there are many of the higher insects, as the bees, ants and wasps, 
who are fortunate in possessing the power of rapid motion, unfailing 
protection and well-developed senses,, and who would seldom be 
hampered in the quest of food, but how would the lower orders of 
insects fare, were it not for the marvelous stratagems that nature has 
taught them? Indeed, they would not fare at all, for if they were 
deprived of these instinctive strategic methods of obtaining their 
daily sustenance, such insect races would soon become a thing of the 
past. Should events of this nature come to pass, then even the bal- 
ance of nature might be seriously affected. 

Although many cases might be shown in which insects and their 
near relatives have been known to live by their stratagems, I shall 
endeavor only to describe the methods employed by four of the most 
interesting groups. 

Through the long summer days these marvelous things are fre- 
quently before our very eyes, yet they pass unnoticed, so accustomed 
are we to neglect that which is the subject of daily occurrence. The 
webs of spiders for instance: What if we had never known of this 
marvel! Would it seem any more incredible to find an animal spin- 




I'.pciia insularis 
An orb-building spiik'r laying her eggs. Tiiey are afterwards eovered in a spliere of silk. (.iie.uK eiil.ui 



A 



INSECT AND OTHER STRATEGISTS 103 

ning out long silken threads; weaving these threads into nets more 
perfect than any ever made by human hand and then suspending them 
with the best judgment where the wished-for prey is most abundant? 
Indeed it would not be more wonderful, but in this case, as in so 
many others, we neglect the actions of the tiny creatures, which in 
the larger ones would excite our admiration and endless attention. 
In fact, the minuteness of the creature renders web-building even 
more wonderful in the eyes of those who see nature as she really is. 

The spiders might well be termed the Icings of strategists, for their 
beautiful nets of glistening silk are among the most wonderful of 
creations. The spiders are divided into many groups, but the orb- 
builders, the platform-builders and those individuals who build no 
webs at all belong to the most interesting families. 

The first group^ constructs those exquisite geometrical figures, so 
wonderful and complicated and so common that we seldom stop to 
realize their beauty. They hang their webs in window corners, door- 
ways, between branches of trees and in many other convenient situa- 
tions where their prey is likely to be abundant. The silken threads 
which compose the webs of the orb-builders, are extremely sticky, 
consequently an insect seldom gains its freedom when once entangled 
in these death traps. 

Many of the orb-builders sit motionless in the center of their webs 
while waiting for their prey, but the cunningest of them hide at a dis- 
tance within a tiny bower of leaves, which are carefully shaped and 
then basted together with soft white silk by the spider. From the 
very center of the web, the creature spins two long delicate threads 
which run into the opening of the bower. These it clasps in its front 
feet and through them, the slightest motion of an entangled insect is 
transmitted to the hiding cannibal. 

^ Epeiridse. 



I04 INSECT BEHAVIOR 

The platform-building group^ constructs large stages of silk in all 
sorts of situations, but they are particularly fond of window-sills 
where their huge webs are often found. At one end of the stage a 
large silken tube is constructed in which the owner hides and from 
which it darts, upon seeing an insect alight upon the platform. The 
silk of these spiders is not so sticky and would seldom serve to entan- 
gle an insect; thus it will be seen that the platform-builders construct 
the fiat white stages chiefly to attract their prey, that they may dart 
from their hiding place, seize and devour it at leisure. 

The third and fourth groups^ embrace some of our largest and most 
powerful harmless spiders. These however, do not build webs, but 
simply move about through the grass in fields or in other places fre- 
quented by their favorite insect food. In fact, they literally stalk 
their game, creeping up stealthily and then springing upon it from a 
distance of several inches. 

Occasionally these spiders will construct a flimsy silken tube under 
a stone, but the majority dig deep burrows in the fields which they 
inhabit and their big hairy heads may be frequently seen squinting 
from the mouths of their subterranean homes. 

One of the most interesting cases of insect strategy is the method by 
which the oil beetle^ succeeds in placing its young within the nests 
of bumble bees, upon whom they are parasitic when young. The oil 
beetle is well named from the fact that it has the curious ability of 
discharging a noxious oily fluid when attacked by an enemy. 

Towards the latter part of summer these big blue-bodied insects 
may be seen clumsily walking and tumbling among the early fall 
flowers which the bumble bees are sure to visit in their search for 
nectar. One unfamiliar with these two insects would not suspect the 

^ Agalenidae. 

^ Drassidae and Lycosidae. 

3 Meloidae. 




I. A spider which used an empty cicada's shell as a hiding place while waiting for victims to enter its web 




2. An example of spider strategy. The web of this spider, Agalcna n;cvia, was watched t'lom day to day for a 

period of two months. Ninety-eight insects were taken from tiic web, carefully dried and ground up, making 

in all, the pile upon which the spider rests. Only the day catches were removed from the web. llie list of 

insects caught would include moths, buttertlies, bees, wasps. Hies, bugs, grassiioppcis and numerous 

other orders. As an example of siiccessfid strategy in the capture of food it is unique 



',1 



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INSECT AND OTHER STRATEGISTS 105 

close relation which exists between their simultaneous reappearances, 
for the oil beetle is out on business which, unhappily enough, will 
prove detrimental to the welfare of the bee's future household. The 
beetle's reason for climbing among the flowers is to lay her eggs upon 
their blossoms; an intruder to be sure upon the property which in all 
nature seems justly and only that of the hard-working bees. In the 
course of a few days the beetle's eggs hatch out into tiny six-legged 
creatures, utterly unlike their parents. Later when the Bumble bee 
comes to gather her store of honey, these active little insects jump 
upon her back and, clinging fast to her hair, are carried to the nest, 
where first they eat the bee's own eggs and later the food which she 
has stored up for her young. 

Another instanceof thestratagems of insects in procuring their prey 
is that of a remarkable insect called the ant lion.^ It is widely sep- 
arated from the race of insects which includes the oil beetles, but it is 
perhaps the most interesting of all preying insect creatures. It is, in 
reality, the young of a certain nerve-winged insect, somewhat resem- 
bling a dragon fly. It is about an inch in length, and the outline of its 
body is more or less triangular, the widest point being at the tail end. 
It has six powerful legs and the mouth is supplied with two incurved 
jaws which give the insect a frightful appearance. Its sole food con- 
sists of the juices of other insects, particularly ants, but on seeing the 
lion for the first time, it hardly seems possible that it could ever secure 
a single meal. Its pace is slow and tedious, but worst of all it can 
walk in no other direction than backwards! What chance would it 
have with a nervous, fast-moving ant? It could not give chase, and 
to stay motionless would be equally ridiculous, for its grim appear- 
ance would be sufficient to impress upon all insect wanderers, the 
prudence of keeping at a respectful distance! The ant lion's appetite 

^ Myrmeleonidae. 



io6 INSECT BEHAVIOR 

is tremendous and it will seldom partake of food unless it has first had 
the joy of killing it. 

Here again the insect accomplishes by artifice what its ordinary 
unaided efforts would have been unequal to. It digs in dry loose 
sand a conical pit in the bottom of which it lies concealed, and there 
seizes those unfortunate ants which, chancing to stumble over the 
edge, are precipitated down the sloping sides into the lion's waiting 
jaws. Sometimes the ant is able to stop half way down, regain its foot- 
ing and scramble madly for the top. No sooner does the ant lion per- 
ceive this than, shaking ofif its inactivity, it ludicrously shovels sand 
upon its head with its front feet and hurls it vigorously upon the body 
of the escaping ant. This heavy shower from below invariably starts 
the sides of the pit to slide under the unfortunate insect's feet and at 
length it is carried down to the greedy devourer in the bottom of 
the pit. 

The methods employed by the ant lion in building its pitfall are 
extremely interesting and I must not fail to mention the fact that we 
have a species of this remarkable insect occurring quite commonly in 
the United States. Many accounts have been written of their curious 
habits, both in this country and in Europe. The following is an 
extract from a paper written many years ago by Reaum, and is an 
admirable description of an ant lion's energy in constructing its pit: 

"Its first concern is to find a soil of loose dry sand, in the neighbor- 
hood of which, indeed, its provident mother has previously taken care 
to place it, and in a sheltered spot near an old wall, or at the foot of a 
tree. This is necessary on two accounts : The prey most acceptable 
to it abounds there, and no other soil would suit for the construction 
of its snare. Its next step is to trace in the sand a circle, which, like 
the furrow with which Romulus marked out the limits of his new 
city, is to determine the extent of its future abode. This being done, 
it proceeds to excavate the cavity by throwing out the sand in a mode 




The fishing net of a hyiliopsychid 
The maker of the snare is shown at the right. These creatures swarm in hrooks. Greatly enlarged 



INSECT AND OTHER STRATEGISTS 107 

not less singular than effective. Placing itself in the inside of the 
circle which it has traced, it thrusts the hindpart of its body under thq 
sand and with one of its forelegs serving as a shovel, it charges its flat 
and square head with a load, which it immediately throws over the 
outside of the circle with a jerk strong enough to carry it to the dis- 
tance of several inches. This little manceuvre is executed with sur- 
prising promptitude and address. A gardener does not operate so 
quickly or so well with his spade and his foot, as the ant lion with its 
head and leg. Walking backwards and constantly repeating the proc- 
ess, it soon arrives at the part of the circle from which it set out. It 
then traces a new one, excavates another furrow in a similar manner, 
and by a repetition of these operations, at length arrives at the center 
of its cavity. One circumstance deserves remark — that it never loads 
its head with the sand lying on the outside of the circle, though it 
would be as easy to do this with the outer leg, as to remove the sand 
within the circle by the inner leg. But it knows that it is the sand in 
the interior of the circle only that is to be excavated, and it therefore 
constantly uses the leg next to the center. It will readily occur, how- 
ever, that to use one leg as a shovel exclusively throughout the whole 
of such a toilsome operation, would be extremely wearisome and pain- 
ful. For this difBculty our ingenious pioneer has a resource. After 
finishing the excavation of one circular furrow, it traces the next in an 
opposite direction; and thus alternately exercises each of its legs 
without tiring either!" 

There is one other insect, a Caddice worm,^ well worthy of a place 
among these instinctive strategists. This creature lives under the 
water. It is a true fisherman in every sense of the word, for it catches 
its food by constructing a silken net in the current of the stream which 
it inhabits. The mesh of this net is almost perfect in its symmetry, 
each strand of silk being fastened at a right angle with the one next 

^ Hydropsychidae. 



io8 INSECT BEHAVIOR 

to it. They are funnel-shaped affairs and the insect is cunning 
enough to always place it so that the running water enters through the 
largest end, thus keeping the net tight and in one position. The insect 
spends the majority of its time under stones or pieces of old water- 
logged wood, visiting its net when in need of food, and finally leaves 
the water after many months, in the form of a filmy-winged insect 
known as a Caddice fly. 

How marvelous it all is, that nature has supplied each and every 
one of her creatures, not only with a method of finding their proper 
food, but, as in the cases which I have just described, she has shown 
them how, by artifice, they may capture with ease and no loss, of 
energy, their desired articles of diet. 




Ants surrounding and pillaging a larger one bearing a pupa. Twice lite size 




Brown ants transporting apliids to their underground nest 
One ant may be seen gently lowering an aphid to a waiting porter whose head protrudes from the ground. A 

third ant looks on from above. Enlarged twice 




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CHAPTER XIV 

OBSERVATIONS ON ANTS 

AS far back as one may search through the entomological 
literature of the past, there will be found records of ant 
behavior. Ever since man has been civilized to the degree 
of recording events, he has realized how wonderful is the 
highly organized social life of these insects. 

So much has been said in fact, regarding their actions, that it has 
become difficult indeed to record anything new, and all but impossi- 
ble to relate any of their known activities in a new enough manner 
to be entertaining. 

It is strange, however, that no one has attempted to bring us face to 
face with ants in their daily life, in such a way that it is unnecessary 
to depend upon the imagination for the actual picture. Poets and 
artists have sketched them and sung their praises, scientists have gone 
minutely into the significance of their behavior, yet who has honestly 
given the camera its chance? 

With this idea in view I have gathered together the material for 
this chapter. However meagre the results, they have been dearly 
bought by many failures and experiences that can be only realized by 
one who has worked in the field of insect photography. 

Let us wander out for a time into the, lowly world of ants, down 
among the grass and earth, or perhaps in the heart of some aged and 
broken tree of other days. Let us live among these creatures them- 
selves, watch their activities and perhaps discover something new. 
There, at the base of the old maple, where its trunk enters the 

ground, is a tiny pile of wooden pellets. Some five feet above, a car- 

109 



no INSECT BEHAVIOR 

penter ant ^ thrusts her head from a crack in the ancient bark. In 
her jaws is a bit of wood debris from the work of enlarging the nest 
within, where other individuals of her kind are cutting away the fiber 
with their powerful jaws. 

The ant that we are watching is only a cog in the great machine 
that makes up the colony and her part of the work is simply gathering 
these wood chips and carrying them to the outside of the tree. Here 
she either drops or transfers them to other porters who carry them 
some distance away from the spot where the nest is being constructed. 

Several porters are also assigned to the task of removing the pellets 
which are dropped at the base of the tree, and if we were to watch 
long enough, the pile which first attracted our attention would grad- 
ually be removed until no evidence of activities within the tree 
remained. 

The work of enlarging the home may be carried on by ten individ- 
uals or a thousand, without affecting the regular routine of the ant 
city. As we watch the crack in the bark for the head of the porter 
with her endless wood pellets, other ants are seen hurrying in and out, 
ants of several sizes, bearing a variety of burdens. Occasionally one 
stops to give the characteristic greeting by crossing or touching feelers 
with a fellow worker, a sort of "Same ]Lodge," as it were, but the 
general appearance about the entrance is one of haste, and reminds me 
of the Grand Central Station a minute or so before the departure of a 
popular commuters' train. 

Here is an ant bearing a tiny whitish grub-like object, dead but 
good eating nevertheless for the hungry ones within. Closely follow- 
ing upon her footsteps is a big powerful member of the colony strug- 
gling towards the entrance in the bark, with the entire springing leg 
of a grasshopper. It weighs as much or more than the ant herself and 
the spines upon it must have caused her no end of trouble, yet she has 

^ Camponotus pennsylvanicus. 




I 



South American leaf-cutter ants, paralyzed and dying after being attacked by a smaller species. Note the por- 
tions of leaves which the victims were carrying when attacked. Much enlarged 




A group of ants, all linked together, but dead and motionless when the picture was taken. Greatly enlarged 



OBSERVATIONS ON ANTS iii 

struggled on (who knows from where?) with that bit of food, faithful 
to her queen and colony. 

Into the darkness of the nest she plunges, now assisted by another 
worker. She disappears through tunnels and alleyways and finally 
lands her dainty morsel in some store room far in the depth of the tree. 
All this she has done in utter darkness and it is strange that she should 
be able to work, unaffected, either by glaring sunlight, which she has 
just left, or the blackness of the nest. 

Now let us look within the nesting tree and see the multitude of 
insect life that inhabits its endless tunnels and galleries. A complete 
colony contains one or two fertile queens, whose sole duty is the 
laying of eggs and without whose influence, the lesser personages of 
the tribe would soon lose their instincts and die. Besides these regal 
insects there are a multitude of creatures known as "Workers," unde- 
veloped females in reality, upon whose shoulders the main labor of 
the community rests. Then there are the young males, and females, 
the weaker sex, to become royal mothers after they have left the old 
home in what is known as the "Marriage Flight" with the young 
males. 

New colonies are started in this way by the younger generation, 
who at maturity are actually driven from home by the workers. The 
young males, however, never enter the new nest. Weak and unable 
to provide for themselves, they soon die of starvation or fall easy prey 
to their many enemies. Thus does Nature dispense with these useless 
members when the "Marriage Flight" is ended. 

The young queens are independent, strong and well equipped to 
take care of themselves, as indeed they must be, for each must lay the 
foundations of a new colony. Their first action is to rid themselves 
of their no longer useful wings, which they do with enthusaim, sever- 
ing them close to the body with their own jaws! When this has been 
accomplished the fertile insect crawls into some. tiny crack or cavity 



112 INSECT BEHAVIOR 

and lays her first eggs. This first brood of antlings must be fed and 
tended by the queen herself, until upon reaching maturity they are 
able to take up the labor for their sovereign. Brood after brood are 
hatched and reared and as each ant becomes a finished product she 
assumes her part of the responsibility. Thus, by the end of a season, 
the young queen becomes indeed a royal mother of a loyal army of 
supporters, workers and soldiers. 

Interesting and wonderful are the ants known as the slave makers,^ 
species that actually organize raids upon the nests of ants of another 
species for the purpose of stealing their eggs and kidnapping their 
young. At the start of such a raid, some little resistance is usually 
offered by the tribe that has been attacked, but owing to the sudden 
and unexpected nature of these bombardments, the slave makers are 
often successful. They are fearless and strong and quite willing to 
die, if need be, in attempting to secure an egg or antling from the 
pillaged nest. 

Sometimes the defending insects will form a circle about the nest, 
which serves to keep the enemy o&, until other members of the colony 
have had time to snatch up eggs and young and make for safety by 
some back door or passageway. But ants that have nearly made good 
their escape are often chased, cornered and robbed of their precious 
burdens by the alert and watchful slave makers. 

When the raid has been brought to a successful end, the attacking 
party returns with its booty to the home nest where it is welcomed, 
perhaps cheered by the non-combatant members of the colony. 

The supply of stolen eggs and young are now raised to maturity, 
after which in the case of one species, they become subjected to abso- 
lute slavery. The reflex of this habit upon the Slave Makers is just 
what one would expect; deterioration. The entire work of a nest is 
often put upon the shoulders of the slaves and in some cases, the war- 

^ Formica sanguinea and Polyergus rufescens, both slave-making species. 




Carpenter Ants proceeding to battle. Dead specimens. Slightly enlarged. 
Warrior Carpenter Ant with severed head of an enemy still clinging to it. Greatly enlarged. 
A train of Army Ants. At least five hundred thousand individuals in the train. 
Leaf Cutter Ants of South America showing heads and abdomens eaten out by a smaller 
species of ant. Three times life size. 



OBSERVATIONS ON ANTS 113 

riors of a colony will not even feed themselves, but depend upon the 
slaves to keep them from starving. 

There is another species of slave makers, whose case is quite at 
variance with the insect mentioned above. This ant expends as much 
energy in home building and other work as it does in kidnapping. 
Consequently its home is in a healthier condition than that of its 
dependent, indolent cousin, even though its architecture is a cross 
between the ideas of slave and master. 

But time will undoubtedly develop this ant into becoming more 
and more indolent, as it becomes more accustomed to depending upon 
its slaves. Indolence means the breaking down of its once strong 
home and instincts. Time may even obliterate it. 

Let us leave these creatures already on the downward path to their 
fate. There are other ants to be considered, insects that have learned 
to better themselves. 

There is a tiny family of true bugs, known as Aphids, often bright 
red or green in color, which gather in great clusters upon the stems 
and leaves of plants. They are equipped with a sharp sucking 
apparatus with which to draw the sweet sap from the plants upon 
which they live. Strange as it may seem, many kinds of ants have 
learned to extract the sweet liquid from the bodies of these little 
insects without injuring them in any way. This operation is per- 
formed by stroking the aphid very gently with the feelers and jaws. 
A stimulus is set up by the stroking, whereby the aphid exudes a 
minute drop of honey dew, which is greatly relished by the ant. So 
much have ants become associated with aphids that they are generally 
knowns as ants' cows, and wherever the little creatures are found 
clustered upon a plant, one is almost sure to see the attending ants 
fussing about and tenderly protecting them. 

Under normal conditions, most of the aphids die as cold weather 
approaches, and this the ants appear to be aware of. With them they 



U 



114 INSECT BEHAVIOR 

perform one of their most interesting habits. The first frosty wind 
that suggests the coming of winter, sends the ants scurrying to their 
respective herds. The tiny cattle are tenderly gathered up and born 
away uninjured to the ants' subterranean nests. Here they are placed 
upon exposed roots below the frost line, that the ant colony may enjoy 
a fresh supply of honey throughout the winter, when for the most 
part, the insect world is cold and dead. 

Even more wonderful is the fact that ants have been observed to 
gather the eggs of aphids in the fall, carry them into their nests for the 
winter and in the following spring, place the young cattle which 
emerge from them upon their natural food plants. Here they were 
allowed to remain during the summer in exchange for the honey-sap 
which they extracted from the plants. 

Among such masses of insects as people the ant world, one naturally 
finds a series of happenings, quite similar to the events in the world 
as we know it. Where great numbers of creatures are found living 
together, no matter what they are, or how low they may be in the scale 
of life, there are sure to be disagreements between certain members 
of the race. How these troubles originate is not for me to say, but it 
is true in the ant world, as in ours, that great upheavals often occur, 
usually between colonies of the same species. Starting perhaps 
between two or three individuals, these disagreements often end in 
general warfare between the two factions. 

These ant struggles are true wars, where only death can decide the 
issue, for they fight hand to hand, or better, jaw to jaw, until one ha& 
destroyed the other. The battle is composed of hundreds of warriors, 
each fighting loyally and frantically until its last spark of life is 
extinguished. 

Few people have been fortunate enough to witness one of these 
wars, yet by a strange turn of fate, the author came abruptly upon the 
tail end of a furious battle which had probably been going on during 




Young brown ants tenderly cared for bv their nurses. Twice life size 




Young brown ants brought up beneath a sun-warmed stone. Twice life size 



OBSERVATIONS ON ANTS 115 

most of the previous night. This fight took place between two 
colonies of carpenter ants/ in the eaves of an outbuilding and work- 
shop. When the doors of the shop were opened in the morning great 
numbers of black, mangled bodies were seen upon the floor, covering 
an area nearly six feet in diameter. The creatures had been battling 
in the eaves above the door, and in the fury of the struggle had 
dropped to the floor below. 

There were legs and feelers, several heads and broken bodies lying 
about in profusion, and here and there were little groups of ants, all 
dead, but still linked together in a death grip. Other mangled bodies 
still writhed in agony. There was one huge warrior with the severed 
head of an enemy still clinging to its feeler, and a few couples were 
still fighting furiously upon the floor. 

One could hear a distinct clicking and snapping as the powerful 
knife-like jaws opened and closed upon the unfortunate victims. I 
even saw one little ant with every limb gone and its feelers both cut 
off, still bravely fighting upon its back, with a much larger and quite 
unharmed antagonist. Above, in the eaves, small groups of warriors 
looked down upon the aftermath, as though staring with satisfaction 
upon the scene of carnage which they had left. 

It brought home to me, as no insect event has ever done before, how 
like us these creatures are ! One offends, and the whole innocent race 
suffers, some only slightly to be sure, but others pay with their life 
and blood for the wrong of another! 

The leaf-cutting ants ^ of tropical America during their foraging 
excursions are frequently attacked by a smaller species of ant that 
easily conquer them, thereafter eating out the abdomen and head of 
their captives. This pugnacious ant is a tiny creature, measuring 

^ Camponotus pennsylvanicus. 

^ These insects belong to the genus atta. They grow a fungus, Rozites gongj'Io- 
phosa, upon fragments of leaves, which serves as food for the colony. 



ii6 INSECT BEHAVIOR 

three millimeters in length, and it is remarkable that they are so easily 
able to vanquish the large and powerful leaf-cutters that measure 
eight millimeters in length and possess long legs and powerful 
mandibles. 

The method of attack is interesting. Grasping their large oppo- 
nents by the middle of the tarsi, the minute warriors bend their bodies 
inward, and with head lowered hang on with great strength and 
force. Two or more attack the leaf-cutter at once and apparently put 
it into such a state of panic that no resistance is offered. It is 
probable that the leaf-cutters could easily rid themselves of these pests 
were it not for the fact that they are first beaten by their own fright. 

Observation of this strange state of affairs, existing between these 
two species of ants, led to the following experiments, which I believe 
are worthy of recording. For the purpose of experiment, two vials 
of liquid were produced by grinding some of the dead leaf-cutters in 
a mortar, to which a few drops of boiled water were added. This 
was let stand for several hours before being strained for use. 

For the first experiment a drop of solution, produced from the 
heads and bodies of the leaf-cutters, was injected into the body of a 
vigorous wasp, a creature many times larger and stronger than an ant. 
The insect immediately showed signs of stupor, twitched heavily and 
rubbed its forelegs over its head continually for several minutes, then 
recovered and flew to the window pane. A second injection of the 
same fluid, and a very heavy one, produced the same result, followed 
by recovery and the insect walking away when liberated! There is 
evidently no poison then, in the heads or bodies of the leaf-cutters, 
which, it will be remembered, are the only parts eaten by the smaller 
ants. 

As a second experiment, a drop of liquid made from the thorax of 
the leaf-cutter was injected into a fresh wasp. This resulted in the 
insect's being completely overcome for perhaps half a minute, fol- 



OBSERVATIONS ON ANTS 117 

lowed by part recovery, then a second spell of weakness, more severe 
than the first, violent twitching, then rolling upon the back. A 
second injection of the same fluid resulted in death within half a 
minute. 

From the above it is plain why the attacking ants leave the thorax 
of the leaf-cutters untouched, as it contains material highly poisonous 
to the smaller insects. 

Continuing the work of experiment, a solution was produced 
from the entire bodies of the smaller ants. A drop of this fluid 
administered to a wasp between the second and third pairs of legs 
produced immediate paralysis of these organs. Another injection 
given just in front of the forelegs produced the same result in that 
pair. Now, if the small ants are closely watched during their attacks 
upon the leaf-cutters, they will be seen to attach themselves first to the 
unfortunate insect's legs. Here they cling for a few seconds before 
gradually working their way towards the head of their prey. 

At length they arrive at this point and remain doggedly clinging to 
the mandibles or mouth parts of the larger ant. From what we have 
observed the following is a possible explanation of what takes place: 

The third experiment has shown that whatever part is injected with 
the small ant's poison, becomes subject to paralysis in a very short 
time. The smaller ant attacks the head of the leaf-cutter and the 
latter, as we have observed, makes no effort to use its mandibles upon 
its tiny persecutor. The smaller ant's course is plain. It attacks the 
leaf-cutter's head; paralysis of the muscles governing the mandibles 
and biting parts results and the larger insect can do nothing to protect 
itself against a number of the smaller ones, who soon drag it to their 
lair! 

Before closing this chapter on various phases of ant behavior, that 
I have been able to record from time to time, it is fitting that I set 



ii8 INSECT BEHAVIOR 

down a few notes on the strange army ants of South America/ 

These insects roam the dimly lighted jungles in vast armies, travel- 
ing about from day to day like bands of gypsies. As they progress, 
carrying eggs and young with them, they hunt out and capture all 
insect life that chances in their path. The booty is torn to pieces and 
then borne to their nest, where the queen and nurses, with the tribe's 
precious eggs and young, together with a number of guards, remain in 
safety until the return of the warriors. Scouts are doubtless sent 
ahead from day to day, whose duty it is to find a safe shelter for the 
main army, which follows shortly afterwards. 

At six o'clock one morning my attention was attracted by a long thin 
line of army ants moving hurriedly across the compound. Tracing 
their line of march I soon found them to be moving in a zigzag course 
to a hole underneath some blocks of concrete that had originally 
served as foundations. Evidently they had been moving for several 
hours, perhaps during the night, for a distinct path two inches or 
more in width had been trodden smooth by them. 

Here and there a leaf or twig hindered their progress and at other 
places a depression in the ground called for the unnecessary expendi- 
ture of energy. To overcome these difficulties, a wonderful sense of 
duty was displayed by certain members of the tribe, who formed solid 
living bridges, over which the others passed. Sometimes but a few 
were necessary to bridge the obstacle, but in other places, dozens and 
dozens of individuals linked themselves together to form the bridge 
and complete the road as a smooth, comfortable highway for their 
tribe. 

The ants traveled from five to eight abreast, never in a wider 
column, and the moving army reached from the concrete blocks clear 
across the compound and thence out of sight into the underbrush, a 

^ These observations were made in the jungle near Bartica, British Guiana, in 
May, 191 6. 



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A snowy tree cricket singins 
These insects produce their song by rasping tiicir delicate wings togetiier which c;iuses them to vihr.itc and pro- 

iluce the soinid 



OBSERVATIONS ON ANTS 119 

distance of at least three hundred feet. This is not unusual. They 
move thus for hours at a time and their numbers are enormous. I 
estimate that this particular army contained at kast half a million 
individuals. 

The Army ant remains in no regular home. They are a crowd of 
gypsies, that travel throughout their lives, living upon the land and 
carrying their possessions with them. In the line of march, one 
sees thousands of nurses carrying eggs, larvae and pupae. They are 
usually in the center of the column, guarded on either side by workers 
of various sizes and soldiers with tremendous heads and mandibles, 
shaped like elephant tusks and gleaming like ivory. Now and again 
a lieutenant rushes back along the line, sometimes charging through 
the thick of the column as though keeping order or searching for a 
member out of step that might hinder the march. All is magnificent 
order and system, like a huge splendidly organized army of soldiers, 
efficient to a man and disciplined into machine-like, unity of action. 

By mid-day the army was in its new quarters, encamped and ready 
for the next march or hunt. Meanwhile, until the order comes to 
move, there is much to be done. There are hundreds of eggs and 
young to be cleaned and cared for. They must be guarded and fed 
and kept warm lest injury result and the future of the tribe be endan- 
gered. 

As they clean and brush the youngsters, the nurses gather in great 
clusters throughout the camp, one upon another, sometimes twenty 
deep and scattered everywhere among this living mass one sees the 
gleam of adolescent insects. All about them move other members of 
the clan, passing in and out among the company streets, each bent 
upon some important bit of work that collectively forms the superb 
organization before us. 

They accomplish one great task at a time, eliminating and neglect- 
ing all others, which at other times would claim their attention. A 



I20 INSECT BEHAVIOR 

harvestman^ walks calmly about among the seething multitudes. He 
is undisturbed and quite ignored even by the soldier ants that sur- 
round the nurses and rest in clusters upon the walls of the cavern. A 
wasp has her burrow within the lines also, but she flies in and out, 
bearing prey for her wasplets at will. The entrance to her burrow 
is within half an inch of a solid phalanx of resting ants. Many 
others are moving hastily over the diggings thrown out from her 
nest, but none enters her domain. 

They are a moral crowd indeed, these army ants. Tomorrow they 
may seethe forth in a terrible invasion and before them all insects will 
fall. They will be invincible, merciless, but the order of today for- 
bids slaughter! Within their very camp other creatures move about 
at will, yet the ants obey that strange supreme command to rest. Fate 
is with the wasp and harvestman. 

All is quiet and serene about the camp. There are no signs of out- 
side activity until late in the afternoon. Then, about five o'clock, six 
lines of scouts issue from the cavern. One line travels out to the posts 
of Kalacoon house, another to the west, over the compound in the 
direction from whence the army appeared. Two more parties go to 
the south and again two to the west. Each of these lines extends for 
perhaps fifty feet. They form in single file, or at times two abreast, 
and occasionally a line may be seen returning, while others still 
advance. 

These are doubtless scouting parties, searching out the ground to 
be hunted or traveled next. There are no warriors among them until 
late in the evening, and then only individuals scattered here and there 
by the wayside, taking no part in the activities of their brothers. The 
scouts are of two sizes, both, I presume, workers. 

Within the nest, the nurses, and somewhere, hidden from the 
common horde, the queen still rests, attended by her special ants in 

^ A species of Phalangidea, commonly called Daddy-Long-Legs. 




The typical dragon-fly face, showing the insects' higli- 

ly developed eyes and negligible antennae or 

feelers. Greatly enlarged 



A robber fly with its prey. This insect is gifted with 
comparatively clear eyesight. Greatly enlarged 



hUk 



OBSERVATIONS ON ANTS 121 

waiting. I wonder what the scouts have found, what they have noted 
and communicated in their mysterious way to the commander of this 
supreme army. It is growing dark without and the scouts abroad 
grow less numerous. One by one the stars appear and I wait as 
anxiously as an expectant enemy for the morrow and the outcome of 
the gigantic plan already formulating among those seething hordes in 
the encampment. 

At dawn on the following day, I found the army at its work of 
slaughter. Walking by the forest trail, I was suddenly arrested by 
a strange sound. It was not the sharp noise of snake or lizard startled 
by my approach, nor the scratching of some hungry ant-bird. It was 
a faint, but steadily increasing crackling murmur, unlike all other 
jungle sounds. 

Stopping to listen, with ear bent to the brush, my eye caught sight 
of a line of warrior ants. Their heads were huge rounded knobs, 
bearing curving mandibles far out of proportion to the remainder of 
their bodies. Glancing back along this line of soldiers, I soon under- 
stood the meaning of that strange cracking murmur, for there just 
behind these pickets rolled the main hordes of the army ants. 

Hundreds and thousands, countless myriads of them rushing ahead 
behind their leaders. Some were in rows, others in bands, chains and 
semi-circles. Among them were warriors of two sizes, but these 
were outnumbered a hundred to one by the workers of the tribe, who 
rushed along with the others. 

Every blade of grass, every stone and twig and leaf was searched 
and researched by these fierce creatures in their mad onward journey. 
They came to a large stump and seethed up it in a solid mass like thick 
flowing molasses; up one moment, down the next and on to another 
object, whatever it might be. Thousands of others mounted to the 
leaves of flowers and the foliage of small trees, sending down a shower 
of panic-stricken insects to the waiting crowds below. 



122 INSECT BEHAVIOR 

No living thing turned to give battle. Outnumbered a thousand to 
one none could combat such overwhelming odds. Ahead of the 
army rushed dozens of insects, driven from their habitats and fleeing 
like animals before a forest fire. Some would escape by a miracle, 
but the rule was a few short hops or springs and then death at the 
hands of the multitude. There were roaches and crickets, big cater- 
pillars and beetles, ants of other species, bugs and huge centipedes and 
great numbers of spiders all fleeing for their lives. 

Roaches and spiders were sought in particular. They appeared to 
be first choice. They were torn to shreds at once and carried away in 
still squirming pieces to the nests. Caterpillars, if hairless, were also 
in favor, then spiders, bugs and so on down the list to the less palatable 
creatures. 

What I had heard at first was not the roar of the army itself, but 
rather the fleeing host of other insects driven from their lairs. I saw 
one large spider escape death by a hair's breadth, by jumping at the 
instant of capture from a leaf into the air and there hanging by a 
silken thread until the danger had passed. Other insects that occa- 
sionally escaped were crickets and grasshoppers, their powerful 
springing legs carrying them beyond the line of march. A curious 
fact was that the ants never crossed the more deeply trodden footpath 
in the center of the trail, consequently those refugees who were for- 
tunate enough to pass this line, were safe, and escaped unmolested. 

A large roach endeavored to escape by crossing the main front of 
the army. The creature made several powerful jumps, but each 
time it touched the ground in order to make another spring, its legs 
were grasped by the fearless ants until at length their added weight 
became too great for the roach to lift. In the end it fell, after a brave 
effort to be free, and was instantly torn to bits and carried to the rear. 

Upon being captured and divided, the unfortunate victim is at once 
carried back through the lines to the temporary nest of the colony. 





Photomicrograph through the eye-windows of a fly, of an ex- 
ternal object, placed extremely close to the eve 

A photomicrograph through the same eye, of the same object, 

moved a very slight distance further from the eye-windows, but 

not so far as to be out of focu'; when viewed alone 



OBSERVATIONS ON ANTS 123 

One sees an unbroken line of these returning warriors, each with its 
dainty bit of the spoils. If the captive is too large for one ant to 
carry conveniently, it is distributed in steaks and hams and then 
brought to the den by a dozen individuals. I saw one ant struggling 
towards the nest with a large span-worm. It was far too heavy for 
her to transport alone and, perceiving this, a second individual 
stopped to give assistance. After some difficulty, these two insects 
slung the worm between their legs, stretched it to its full length and 
by grasping it in their mandibles proceeded to the rear. 

Another ant with the body of a wood roach was assisted by a worker 
who held the carrier's abdomen high in the air out of the way of her 
burden, all the way to the nest. 

In observing the movements of the army I became so absorbed, that 
the ants surrounded me without my being aware of it. They threw 
their lines here and there through the jungle for a distance of two or 
three hundred feet in every direction, and while I was in no danger, 
I could not get beyond their rear guards without being attacked and 
severely bitten. As I crossed through them with all haste, they 
swarmed upon my shoes and socks, biting and stinging wherever they 
could get through to the skin. 

The attack of these vile little creatures, whom I learned to hate 
worse than anything else in the jungle, was so painful and poisonous 
that I shall never forget it. It brought home to me, how horrible 
must have been the deaths of those poor black men of Africa, who, in 
punishment, were tied hand and foot and left in the path of the army 
ants! 

It is a strange fact that many other insects were attracted rather 
than frightened away by the army's movements. There were various 
species of preying wasps, who, finding their favorite victims of cater- 
pillars and spiders abundant, and already hunted from cover for them, 
were quick to take advantage of conditions. They would hover above 



124 INSECT BEHAVIOR 

the army like hawks, suddenly diving like lightning upon some dainty 
morsel with which to provision their nests. 

Likewise there were flocks of birds, thus gaining a living at the 
expense of the ants who drove forth their favorite insects. Some 
were tiny species, impertinent and talkative and sombre in color, 
others were larger, decked with crests of snow white plumes. One 
learned to associate these birds and insects, for where a flock of one 
was heard the other was sure to be also. 

For many hours I watched this army "at its deadly work. Then at 
length the fury of their drive diminished. One by one the warriors 
made their way to the temporary den in the heart of a rotting forest 
giant and by afternoon no signs of activity remained upon the forest 
floor. 

Would that I might have seen within that aged and broken tree, 
for there, no doubt, a royal banquet was in progress. Perhaps 
another, more fortunate than I, may some day tell us what goes on, 
when the tired warriors return laden to their queen. My notes are 
but a drop in the bucket, and the army ants have still much to tell us. 




'A harvestman walks calmly about among the seething multitudes." (Page 90.) Greatly enlarged 




The ivory-colored eggs, massed in tiie feathers or fur of the respective host, hatch witiim t\veiu\-tour horns. 

cluster ot greenbottle's eggs. Greatlx' enlarged 



CHAPTER XV 

THE SIGHT OF INSECTS 

OFTEN we have wondered to what extent the sense of sight 
is developed in insects. It has been asked again and 
again. It has been argued from every possible standpoint, 
but for all that it has been answered slovenly, and in an 
unsatisfactory manner. 

Casual observations of the insect world tend rather to convince us 
that its people are alert to movements and dangers, and therefore clear 
of vision. We observe the male of a species searching for his mate. 
Perhaps she is a foot or more away, hidden behind thick foliage. Her 
color blends perfectly with her surroundings, yet how easily after a 
move or two he discovers her and quickly greets her with his love. 

Again we hear a tree cricket, shouting his melody into the summer 
night. Stealthily we creep up, step by step, to the spot from whence 
the tune arises only to have it cease abruptly at the instant of dis- 
covery. 

And so we might sight a thousand cases where apparently insects' 
vision aids them in a successful life. The bug searching its mate, the 
cricket avoiding discovery, the fly escaping its everlasting and greatest 
enemy, the swat, and so on indefinitely. 

But it is strange how modern instruments and facilities for proper 
study, knock one's pet theories in the head. They rather take the 
romance out of things. Surely they leave no room for imagination, 
but after all the truth is best. 

Insects possess sight, it is true, but in most cases it is not in a highly 

125 



126 INSECT BEHAVIOR 

developed state. In order to understand what follows we must first 
become acquainted with the typical insect eye. 

It is not the organ we generally think of, as one sees it in the head 
of a man, a beast or bird, but a compound and vastly different object. 
It is true that upon examining an insect closely we observe two large 
eyes, one set on either side of the head, but if we were to magnify the 
outer shell or cornea of these protrusions, we would find that what 
appears to be a single eye is, in reality, made up of many hundreds of 
smaller facets or microscopical windows, the whole resembling in 
every detail the exterior of a piece of honeycomb. 

Behind each of these facets is an independent eye element of a com- 
plex nature connected with the optic nerve, so that each tiny window 
sees that part of the external object that is directly in front of it. In 
other words, whatever the insect sees is separated into as many parts 
as there are facets. To begin with, then, we learn that insects prob- 
ably see things in mosaic patterns. 

Let us now take a fresh insect and place that part of its eye bearing 
these tiny facets, under the microscope. Through the instrument we 
observe a honeycomb sash, in which the cuticular windows are set, 
and which appear to be quite transparent. 

By the aid of a photomicrographic apparatus, that is to say, an 
arrangement by which we may photograph through a microscope, we 
now mount a minute object so delicately in front of the already 
mounted eye, that by peering into one end of the apparatus, we may 
actually see an external object through the eye of an insect. We are, 
so to speak, inside the fly, looking out. 

For this object a feather from the head of a humming bird was 
chosen. By reason of its very minute size and convenient fan-shaped 
structure it proved ideal to illustrate the qualities of focus in the 
insect's eye. 

In figure 64 we see the result of the first photographic experiment, 




Atli.urnl by a special odor, tlu muflui tln.s come to deposit their eggs. A greenburtk Luing eggs upon the 

head of a dead sparrow. 




The eggs are deposited away from the light, among the feathers, in wounds or in the mouth of the host. Green- 
bottle laying eggs in a starling's bill. Both much enlarged 



THE SIGHT OF INSECTS 127 

in which the feather was placed, the smallest fraction of an inch 
beyond the eye window. It is clear and in perfect focus, even show- 
ing the smallest scales of the feather in fine detail. In each successive 
experiment the feather was moved perhaps one micron further from 
the eye, the result being that its plumes rapidly lost focus until all 
detail was gone. This was in no way due to the use of a too powerful 
lens, as proved by the fact the feather remained in fair focus when by 
itself at a similar distance from the lens, only becoming blurred when 
viewed through the cuticular windows of the eye. 

From these not over-difficult experiments we have the following 
facts concerning the power of sight in insects. In the first place they 
see objects in mosaic patterns. Objects are seen in clear focus only 
when extremely close to the eye. At greater distances, only the out- 
line of the object is visible and beyond a few inches things doubtless 
pass into mere shadows with intervening patches of light. 

Further the experiments tell us that an insect cannot always depend 
upon its eyes. To find its mate, and to sustain life, by securing food, 
it must rely upon the sense of smell. But what of the fly who even 
with its defective eyesight, still avoids your swat so easily? True, he 
cannot see you in clear outline, but remember that you appear to him 
as a gigantic shadow more reaching than that cast by a range of lofty 
mountains. When you make your swat, this great shadow topples 
toward him with fearful speed, but Nature has supplied the creature 
with eyes that exaggerate and a speed that excels a falling avalanche. 

Now it might be argued that these experiments were not really per- 
formed with the actual eye of an insect, but simply with the outer 
coating of that organ, and therefore prove nothing. Perhaps, in part 
such a statement would be true, yet is it not the outermost window 
that governs the quality of sight? A man might possess perfect 
vision, yet were he to stand with his face against a dirty window his 



128 INSECT BEHAVIOR 

eyes would avail him nothing and he would be ignorant of the details 
of what passed without 

And so with the Insect. I believe it is the glass in the tiny honey 
comb sash that governs its sight; and through these minute windows 
the photographs illustrating this article were taken. Whether we 
observe this through a microscope, as we have done, or with a hand 
glass or the naked eye, we will arrive at the same results that we have 
already seen by our experiments. 

Doubtless some insects see more clearly than others. Crickets 
jump at the slightest movement of an object many feet away and 
appear to be so gifted. The robber fly ^ captures its prey upon the 
wing, darting after it as it passes by, but of all these creatures who 
use their eyes to advantage, the dragon flies are, in the opinion of the 
writer, the only insects who depend more upon their eyes than any 
other of their sense organs. 

Dragon flies are primarily predacious creatures, feeding chiefly 
upon mosquitoes, gnats, house flies and other alert and winged insects. 
They dart upon their prey with the ease and swiftness of a hawk, often 
from a great distance, seldom missing their unfortunate quarry. A 
glimpse at the typical dragon fly race, strengthens the theory that they 
are possessors of accurate eye sight. The eyes are huge, covering two- 
thirds of the creature's head, while the antennae or feelers, which are 
the usual sense organs of direction in insects, are scarcely noticeable, 
hair-like appendages. To connect these primary features with the 
creature's habits, can only lead to one conclusion — that the dragon 
flies are possessed of clear eye sight and are exceptions to the general 
rule. 

^Asilidae. See Fig. 66. 




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CHAPTER XVI 

HOW THE GREENBOTTLE DOES ITS DUTY 

SarcophagideB 

AS we stroll by the roadside this bright morning, a breath of 
air brushes ever so slightly across our path. It is a breeze 
at first scented with blooming roses and wistaria, perfume 
gathered from who knows where, and born by chance to our 
nostrils. In an instant it passes on as mysteriously as it came, leaving 
us bewildered by its change to the offensive. It is no longer pleasing. 
Somewhere within, it hits a tiny blow that says decay. A moment 
ago we had forgotten that such a thing were possible, but we are 
awakened now quite rudely. Even today, when Nature displays her 
beauty in a thousand different colors and voices her mood in as many 
varied songs, there is such a thing as decay. 

Exploring the realm of thought for a moment, we wonder why the 
shell of what was life, no matter how tiny, no matter how great, if left 
uncovered, offends us. There must be an explanation to this, for 
Nature does not create a condition or a state without a reason. Being 
human, and therefore curious, wc hunt about with this thought in 
mind, first for the source of the odor. Its function we shall look into 
later. 

Lying stiffly by the roadside, the result of human folly and igno- 
rance we find the offending corpse, a tiny squirrel with lustrous coat, 
marred only by the wound that caused its death. A broken stick and 
an empty shotgun shell close by tell the story of the crime, sufficient 
evidence to convince if not convict. 

Turning over the little animal, we find a surging mass of maggots, 

129 



130 INSECT BEHAVIOR 

a sea of life thriving upon death. They are the offspring of the 
greenbottle flies that hover about. Here indeed is food for thought. 
A repulsive sight perhaps, but let us forget about that part of it, in 
order to realize the beauty of what Nature is accomplishing. 

Nature has long since learned that she cannot rely upon Man to 
restore the life that he has taken nor even to erase his crime by burying 
the corpse, yet she cannot tolerate the sight of death. If she did our 
land would be strewn with the mummies of ages. She cannot bury 
her creatures unaided. Instead she sends broadcast her tainted 
messengers, who marshal others to her aid. Thus we see her reason 
for the odor of decay. 

Attracted by this special odor, the mother flies come from far and 
near to deposit their eggs, thus securing the future of their race. 
Hundreds upon hundreds, thousands upon thousands are deposited 
and hatched until a great army is mobilized upon whom Nature may 
rely. In a short time that which was but a mass of something dead 
and repulsive, becomes the separate bodies of myriad living creatures. 
Every atom of the squirrel disappears and becomes a part of a new 
life. True, the squirrel's bones remain, but they are mineral matter. 
They will go back into the earth where they belong and Nature will 
have restored her balance. 

Examining one of the maggots, we find it to be a soft-bodied 
creature, milk colored, with a head somewhat darker than the rest of 
its body. It is tapered, like a kernel of corn viewed sidewise, the head 
appearing at the narrowest end, and is capable of a rapid rippling 
motion by contracting and expanding its muscles. At birth it is no 
larger than a flattened pinhead and at no time during its life is it sup- 
plied with mandibles or other appendages suitable for tearing or 
masticating its food. The mouth is soft and extremely minute ; there 
are no sharp claws, no teeth. In fact it possesses nothing but two 
weak lips that could scarcely caress their host. How then does such 



^^^- ' '" -ill liiwiMiiir 






«*» ^^^^^H 


b 


1 



Skeleton ot a muskrat 
How the young flies clean up a dead animal, leaving only the bones which go back into the earth as mineral matter 




From left to right the tubes contain, banana, coral fungus, boletus fungus, sugar, gluten, yolk of egg, white of egg 
and cheese. Each tube contains ten young greenbottle flies who were observed to thrive on these fresh- 
foods. Note liquification of foods in tubes 5, 6 and 7 



HOW THE GREENBOTTLE DOES ITS DUTY 131 

a weakling surmount the difficulties of feeding upon the toughened 
corpse? To answer this we must experiment in the laboratory. 
Such a question cannot be decided by theory. We must secure the 
eggs of the fly, hatch them under various conditions and note what we 
can of their methods. 

For our purpose, we place several dead objects in the sunlight. In 
a very short while there are a dozen flies about the game. Soon there 
are a thousand ivory eggs, and in a day, as many wriggling offspring. 
The first experiment is a huge success. We have a multitude of eggs 
and young. Let us gather some and continue. 

In the laboratory we prepare twelve cubes of fresh raw beef, each 
weighing three grams. Six of these are placed in separate test tubes 
with cotton stoppers to prevent evaporation and a dozen freshly 
deposited eggs of the fly are added to each. The six remaining cubes 
of beef are placed under a glass bell as a control. 

In a short time the inoculated tubes are alive with young flies and 
we notice that each individual is constantly surrounded by moisture. 
As the youngsters increase in size from day to day, the puddle in 
which each one feeds grows in proportion until at length after five 
days the meat within each tube is completely liquefied and about the 
consistency of thick cream. Under the glass bell conditions are 
totally different. Here the meat cubes are in exactly the same form as 
when placed there five days before. Perhaps they are slightly darker 
in color, but they are still in the form of cubes and quite as solid as 
ever. There is nothing which suggests a liquid state such as we see 
in the test tubes where the young flies have been feeding. 

Continuing our experiments, we dip a piece of blue litmus paper 
into one of the tubes of liquefied meat. It turns almost at once from 
blue into a faded red. This is a simple chemical test which shows 
the contents of the tube to be slightly acid. We find that the same 
is true of the six inoculated tubes. Now in the human body there 



132 INSECT BEHAVIOR 

exists a ferment in the gastric juice known as pepsin, which in the 
presence of a weak acid converts proteids or tissue-forming foods into 
peptones, that they may be easily diffused through the membranes and 
used in the actual building and heating of the body. The strip of 
litmus has shown us the presence of just such an acid in each tube of 
liquefied meat. 

Here then is the solution of the mystery surrounding the young 
flies' method of feeding. They are born without an equipment, suit- 
able for actually chewing, but Nature has supplied them with a 
powerful expectorant capable of dissolving flesh into bouillon. Like 
so many drunkards, they drink their dinners, but their intoxication 
which comes only in the form of life, rids us of decay, a menace to 
our health and welfare. 

From a chemical point of view, the young greenbottles digest their 
food in much the same manner that we do, but being unable to chew 
and swallow solids, they exude their pepsin first upon the food, con- 
verting it into liquid, which is then easily drawn into their suckling 
mouths and swallowed. Indeed it is a most admirable method, one 
that we would not be loath to mimic were our jaws undeveloped, our 
mouths toothless and our limbs unsprouted. So much for the young 
flies' method of assimilating their food. 

Let us make the final experiments so that we may realize how this 
insect is of service to mankind. There are fifty thousand species of 
flies and we cannot condemn them all like the filthy house fly and the 
fever mosquitoes, which are recognized outlaws of humanity. In the 
ranks of this huge winged army we find insects doing good as well as 
bad, and the greenbottle is one of them. 

For our experiment we procure a banana, two kinds of fungi, 
some granulated sugar, the boiled white and yolk of an egg, some 
gluten and a bit of cheese. It is a weird collection to be sure, but it 
will serve our purpose very well. We have now eight different food 



HOW THE GREENBOTTLE DOES ITS DUTY 133 

materials, fresh and wholesome in every particular, and varied 
enough, one would say, to suit the most fastidious taste. Such a free 
lunch should tempt the most abstemious. 

During the day many greenbottles are attracted to the repast. They 
find the lure attractive and satisfying to their own mature appetite, 
but for all our trouble no eggs are laid upon the stores. This is 
indeed mystifying. Can it be that such excellent provender is 
unworthy of the fly's offspring? A curious state of affairs this, that 
such a puny creature must reject the fats, sugars, proteids and other 
nutrients capable of sustaining life in man himself. 

Let us collect our foods and place each in a separate test tube, 
previously inoculated with a number of young flies. The youngsters 
are not half so particular as their parents. They feed happily enough 
on what we have provided and the tide of liquid rises rapidly in each 
tube. The egg, the fruit, the dry gluten, all but the sugar are con- 
sumed with relish by the maggots. 

We have seen that the mother greenbottle ignores these fresh 
foods for the purpose of laying her eggs, but we know from the 
experiment just performed that her young will thrive upon them. 
Perhaps this is common knowledge between the fly and ourselves, yet 
she selects only putrefying matter in which to bear the fruit of her 
love, that our world may be saved from the menace of decay. 

No doubt the greenbottles carry germs, no doubt they bring an 
occasional sickness to those who come in contact with them, but unlike 
the house fly, they are at the same time altruists, working for the 
public good. Like the street cleaner and the hobo, both are dirty, 
yet one is a menace, while the other rids us of one. 



CHAPTER XVII 

SOME INSECT EXPERIMENTS 

YONDER near the forest's edge, a neglected, grass-grown 
wood path winds its silent way into the sombre, shaded 
depths of the virgin growth. In the center of the path 
stands a mound of dry, brown earth, protected from Na- 
ture's elements by the thick, dark foliage above. The mound is nearly 
three feet in diameter and stands some eighteen inches in height, for 
all the world like a miniature volcano in a setting of giant trees. 
Indeed, even the lava seems to be there, pouring downward in an ever- 
changing stream, as if impatient to destroy some tiny city at the 
mountain's base. But this is not the eruption of a fairy Vesuvius, 
which we are witnessing, nor is it even an unusual sight, but simply 
a great thriving insect city, wherein live some forty thousand mound 
ants^ whose unceasing labors cause the whole metropolis to writhe 
lik streams of molten lava! 

Among the numerous volumes which have been written upon insect 
life we seldom find one in which the ants are not credited as being the 
most marvelous of all insects. The actions of these creatures and the 
deeds which they accomplish would furnish sufficient material to fill 
many a volume of portly size, and indeed much has been written upon 
the subject. Marvelous is the manner in which they feed and care for 
their young and wonderful the loyalty of the subjects to their queen 
and their city. The storing of proper food for the winter and the 
capturing of Aphids or "Milch cattle," from which the ants extract 
a sweet nourishing liquid, are other interesting examples, all of which 

^ Formica exsectoides. 

134 




Nest of the mound-building ants 
One-twi'lttli natural size 



SOME INSECT EXPERIMENTS 135 

tend to strengthen one's belief in the intelligence of these industrious 
inhabitants of our world. But sooner or later, the very insect who, 
perhaps, by its marvelous actions, has held our rapt attention, or 
caused us to exclaim in astonishment, will display, but a moment 
later, such a ridiculous lack of logic that we are at loss to understand, 
and our belief in intelligence will be rudely shaken. But perhaps not 
permanently, for it is true that among nearly every large colony of 
these insects one will find an occasional example wherein an individ- 
ual seems really to leave the beaten track of instinct in which its 
forefathers have traveled unwittingly for hundreds and hundreds of 
years. 

Let us follow, for a moment, the movements of a single member 
of this colony of mound-builders, who is discovered laboriously 
endeavoring to drag the remains of a cricket many times its own size 
to the insect city, some twenty feet distant. 

In the same circumstances, a man would have soon given up the 
task, for every twig, &very leaf and every stone in the path played a 
part in hindering the progress of the hard-working insect. But the 
ant would not abandon such a dainty morsel of food, even had it been 
three times as heavy, and indeed she might have soon reached her 
destination had I not cautiously clasped the cricket by one of its 
antennae or feelers with a pair of slender forceps. The ant was greatly 
troubled at finding her burden immovable, but she soon commenced to 
investigate, and finally, after some minutes, came upon the closed end 
of my forceps. Vainly she tried to free the insect from the grip of 
steel and finding herself unequal to the task, she soon made off in the 
direction of the mound. Now when perhaps fifteen inches away, the 
ant suddenly turned, as if by some idea or impulse which must be 
obeyed. Going straight to the feeler, which was still held by the 
forceps, she chewed it free with her powerful jaws and once more 
made off, this time in possession of her well-earned burden! 



136 INSECT BEHAVIOR 

Of course it is probable that upon her return, the ant came by 
accident directly to that part of the cricket which was being held in 
the forceps. Nevertheless, it must be remembered that this time 
the ant freed her prize by chewing through the cricket's feeler, an 
action which had not, apparently, occurred to her when her journey 
was first arrested. Although this fact is not a very remarkable one, 
it is true that the ant was efficient in adapting herself to the cir- 
cumstances, which were quite unusual. In such cases instinct is sup- 
posed to be deficient. 

Now let us watch another ant, an inhabitant of the same mound, 
who is also struggling homeward, bearing the remains of some dry 
and lifeless insect. 

After towing her burden backwards for perhaps twelve inches, the 
insect came upon a tall blade of grass, fully a foot in height, which 
was growing directly in her path. Here I expected to see the ant 
circumscribe the base of the stem, but what stupidity! Instead of 
executing this simple manoeuvre, she climbed first to the top and 
finally down again upon the opposite side of the blade, probably with 
the idea that she had covered with ease a considerable portion of the 
homeward journey. 

These two ants, which we have followed with their burdens, were 
undoubtedly children of the same queen, yet while one was quite 
competent under extraordinary conditions, the other lacked sufficient 
power of perception to have prevented herself from accomplishing 
a useless feat. 

An interesting insect for experimental purposes is the Sphecid 
wasp,^ the largest and most powerful of our Eastern wasps. This 
insect digs a deep burrow in sandy soil, at the end of which two or 
more elongated chambers or cells are constructed. In each of these, 
the insect places a single cicada or "Locust" that has previously 

^ Sphecius speciosus. 



SOME INSECT EXPERIMENTS 137 

been paralyzed, but not killed, by the wasp's terrific sting. Now she 
lays an egg upon the breast of each of the unfortunate cicadas. When 
this has been done the burrow is sealed with earth and the young 
wasps feed upon the paralyzed insects until they reach what is known 
as the pupal state. In this form they spend the winter, issuing as 
perfect insects in the following spring. (See chapter XI.) 

It is true that the cicada is larger and heavier, even than the power- 
ful Sphecid, and it will readily occur to the reader, that to carry 
such an ungainly burden through the air, would be an extremely 
difficult undertaking. But here Nature has assisted the insect in ac- 
complishing her function by supplying a pair of powerful upturned 
hooks or tongs, one of which is situated upon the under side of each 
of the wasp's back legs. These she squeezes against the cicada's sides 
and thus secures her burden during the overland journey to the 
burrow. 

During the latter part of August, the writer captured one of these* 
insects, together with a cicada, which it had recently paralyzed. The 
carrying hooks were then carefully removed from the Sphecid's legs 
and after several hours, the insect was replaced beside the same cicada 
which it had been carrying when captured. This was within a few 
feet of the burrow. Now a remarkable thing happened. The wasp 
paid not the slightest attention to the cicada, but flew rapidly away 
among the trees. This I had expected, but to my surprise she re- 
turned to the burrow within an hour, carrying another victim, appar- 
ently in her first and second pairs of legs. The cicada was suspended, 
tail down, in a line perpendicular to the wasp's body; the two insects 
forming the letter T while in the air. 

This is a most remarkable case, as the Sphecid left the instinctive 
rut so minutely traveled by her ancestors and instantly adapted her- 
self to the most extrinsic circumstances imaginable. 

Equally interesting are the results of two experiments upon differ- 



138 INSECT BEHAVIOR 

ent species of the same group of insects, which were recently observed 
at close range by the author. These experiments are well worthy 
of note, from the fact that a vast contrast in adaptability was discov- 
ered between two insect species, so entirely identical in their anatomi- 
cal structure and so closely related in their classification that they 
should have been equal to each other, even under the unusual cir- 
cumstances in which they were placed. Yet in one of these experi- 
ments it was shown that a certain species possessed the power of in- 
stantly distinguishing between right and wrong, while the other made 
plain its inability to leave the beaten path of innate propensity. 

As I have said, the insects in question were both species of wasps; 
one the common paper wasp ^ and the other the common blue mud- 
dauber.^ 

Although they are much alike in structure, their habits are quite 
at variance, as we shall presently see. 

The paper wasps are a social species; that is, they live in a colony, 
with a common den, which in this case consists of a group of paper 
tubes for cells suspended by a central stem from the undersides of 
overhanging stones or more often from old beams and timbers in 
barns or sheds. The paper for the nest is manufactured by the wasps 
from wood pulp, which is scraped from unpainted lumber and then 
mixed with a glutinous substance, which the insects possess. A large 
nest will contain in the neighborhood of three hundred cells, but the 
great majority are complete when one hundred have been constructed. 
In each of these cells an egg is laid by the queen and the young are 
fed by the other members of the colony until their period of help- 
lessness is at an end. Their food consists of chewed up spiders and 
other insects, mixed with a certain amount of nectar, and is un- 
doubtedly good. Thus it will be seen that the paper wasps are of a 

^ PoHstes. 

^ Chalybion caeruleum. 





Cecropia caterpillars twenty-five days old. Life size 



Twenty-six day old cecropia caterpillar casting its 
skin. Life size 





Caterpillars of the cecropia moth just after the second 
cast. Reduced 



Eggs of the cecropia moth on an apple leaf. .Natural 
si/e 



SOME INSECT EXPERIMENTS 139 

domestic turn of mind, and quite different in habits from their mud- 
daubing cousin, who is a restless, nervous creature of a solitary nature. 

This insect constructs from five to fifteen cells of rich grey mud, 
which, upon hardening, becomes quite substantial. The nest is placed 
in situations similar to those which the paper-making species select. 
Like the Sphecid wasp, the mud-dauber fills each cell with paralyzed 
insects, which in this case consist of small spiders. Then, after laying 
a single egg in each, she seals up the opening with mud and leaves 
the young wasps to shift for themselves. 

For the first experim.ent, a mud-dauber's nest was selected which 
was discovered under the overhanging roof of an old woodshed. The 
afifair consisted of ten cells, all but one of which had been sealed by 
the wasp, who, by the way, quickly appeared upon the scene, carrying 
a small, reddish spider. The burdened insect flew directly to the 
nest and after carefully inspecting her cargo, to make sure that it 
was in perfect condition and quite proper to serve as food for her 
offspring, she entered the remaining empty cell. To store these spiders 
to her satisfaction required quite some time, but when once they had 
been suitably placed our industrious insect lost no time in hurrying 
away to gather more victims. This manoeuvre was repeated on an 
average of every seven minutes, but upon her tenth return to the nest, 
she carried a small pellet of mud instead of the usual spider. This 
she carefully placed upon the open end of the cell and after flattening 
it somewhat with her head and forefeet, flew off for more. 

At this point I intervened in behalf of my experiment, and as a 
consequence thereof, the sealed portion of the entrance, and the spi- 
ders, were entirely removed from the cell. Within a very few minutes 
the wasp returned, bearing its second load of mortar, and this, as 
upon her previous visit, she cemented to the opening of the cell. Now 
the wasp thrust her head through the half-closed entrance and after 
apparently inspecting the empty interior, again flew away, this time, I 



HO INSECT BEHAVIOR 

thought, in search of a new supply of spiders. But this was not the 
case, as we shall see. I now left the immediate locality of the nest, 
fearing that perhaps my continued presence would alarm the subject 
of my experiment. In an hour I returned, only to find that the wasp 
had ignored the fact that the cell had been emptied and had com- 
pletely resealed it without replacing the spiders or her egg. 

In this case the insect clearly demonstrated her inability to notice 
even such a radical alteration as had been made in the cell contents 
during her short absence. She simply proceeded to accomplish a 
certain regular course of inborn events and, owing to the fact that it 
did not occur to her to alter any of these, even under the present cir- 
cumstances, it is plain that there existed nothing in the form of in- 
telligence, but simply innate muscular actions of a reflective or un- 
conscious nature. 

But now let us turn to the subject of my last experiment, which; it 
will be remembered, was the closely related paper-making cousin 
of the mud-dauber. As I have stated before, the paper wasps do 
not seal up their cells, nor do they even store them with nourishing 
food for the young. Owing to this state of affairs, it would, of course, 
be impossible to effect a similar alteration upon their nest as upon that 
of the mud-dauber. But the purpose of my experiments was not sim- 
ply to place the two species in identical circumstances, but to dis- 
cover, if when placed under extraordinary conditions, either would 
display in their actions any evidences of intelligence; or in fact any- 
thing which might give us better reason for believing that insects are 
sometimes governed by a power above mere instinct. 

At the time of this experiment, the paper wasps were adding sev- 
eral new cells to the nest, which had grown too small for the rapidly 
increasing colony. These new cells were nearly finished ; all but one, 
and of this perhaps a third had been constructed by the tireless in- 
sects. As I reached the nest, a wasp was seen working upon the un- 



SOME INSECT EXPERIMENTS 141 

finished cell, but she soon flew away in search of a new supply of 
pulp. When she had gone far enough to insure my feelings against 
her sting, the other members of the colony were quickly put aside 
and the cell was then suddenly finished by human hand, assisted by 
a small tube of greyish court-plaster. 

In a few minutes the wasp returned and flew directly to the cell 
which I had so kindly completed for her. But she apparently con- 
sidered my work as being far from the required standard, indeed she 
must have thought me downright fresh, for soon my carefully made 
cell of court-plaster was cut away from the nest and viciously ejected 
by the wasp, who was now in a temper to be respected. 

On the following day I returned to the nest with another cell, 
but this time I had moulded it of papier-mache; thus it was identical 
in size, color and texture, with those which the wasps construct 
themselves. Once more the wasps were put out of the way, and while 
the one who had been allowed her freedom upon the previous day 
was again collecting pulp at a respectful distance, I cut away the 
cell which was now nearly finished, and fastened the papier-mache 
one in its place. Upon her return to the nest, the wasp displayed 
the same disgust at my inability to construct a cell, as upon the oc- 
casion of my original effort. Consequently the object of my labors 
met a fate similar to that which the first cell was subjected to! 

How quickly this insect recognized the uselessness of these man- 
made cells, for indeed I had left them open at both ends. Yet her 
very near relative, the mud-dauber, was blind to the fact that her 
nest cell had been trifled with and her egg removed, which is an affair 
of much greater importance! But why these differences, even among 
insects almost of the same flesh and blood? That is what we do not 
know; it is a question for which we have yet to find an answer. But 
however that may be, it is evident from the results of the experiments 
which I have just described that in cases unlikely to be provided for 



142 INSECT BEHAVIOR 

by instinct, insects will occasionally adopt means whereby their ob- 
jects may be effected. And if it be true, as we now believe, that all 
instincts arose through successive generations preserving habits which 
happened to be of benefit, then insects must gain knowledge from ex- 
perience, which would appear to be impossible were they not gifted 
with a slight amount of intelligence. 



-^ 



J 




Female cecropia moth. Two-thirds life size 





Full grown cecropia caterpillar just before com- 
mencing its cocoon. Life size 



Newly completed cocoon of the cecropia moth. 
Two-thirds life size 



CHAPTER XVIII 

THE CECROPIA MOTH 

Samia cecropia 

WHEN the first fireflies are sparkling here and there 
among the fresh dark foliage, and when the migrant 
warblers from the Southland have ceased to fill the 
evening air with their sharp clear voices, it is then that 
the great cecropia moths are on the wing, hovering silently among 
the newly opened blossoms, for it is the first real sultry night in June. 
During the day they have been creeping forth from their big winter- 
worn cocoons to dry their wings, long cramped and matted. But 
now it is night, it is time to venture abroad into a new world, perhaps 
to mate and to start a new generation, perhaps to enter the open net 
of an eager entomologist or perhaps to feed some hungry, prowling 
animal. 

Soon after this first night of freedom, the female moth who has 
been fortunate in avoiding its enemies is ready to lay her eggs. 
These are deposited in small white clusters upon the underside of the 
leaves of our cultivated fruit trees. Unfortunately we cannot alter 
this law of nature and thus the cecropia must fall in our estimation, 
like so many other insects, wonderful and beautiful to look upon, but 
"Noxious" as the sentiment-lacking entomologist must class them. 
If the moths would confine their attacks to the larger trees, such as 
the apple or pear, the cecropia would do little or no damage, as the 
moths lay but a few eggs upon a single tree. However, when these 
occur upon a small currant or other fruit bearing bush, as they fre-: 

quently do, it is but a very short time after the caterpillars hatch 

143 



144 INSECT BEHAVIOR 

out before the foliage is entirely consumed. The bush is then ruined 
until the following spring. 

Ten days after being deposited upon the food plant, the eggs split 
open in the center. One unfamiliar with the cecropia's life history 
would be very much surprised to see the tiny, black-spined cater- 
pillars which emerge from them. At this age, they are jet black and 
scarcely a quarter of an inch in length. The body is armed with 
six rows of eleven and sometimes twelve stout spines, which, no 
doubt, are terrifying enough to their natural enemies. When about 
five days old, a tiny orange ring appears around the base of every 
spine. This is a sign that the larva, as the caterpillar is scientific- 
ally termed, is about to cast its skin. That is to say, it has grown 
too large for its birthday suit and therefore must have a larger one. 

The cast is intensely interesting to watch, as the old dry skin may be 
seen to split, at first near the head and finally down the back until 
it reaches a point directly above the last pair of legs. At this juncture 
the larva simply crawls out, bearing a new suit of the brightest 
yellow, with steel blue spines, leaving the old black cast-off sticking 
to whatever substance the larva had fastened it to. 

The cecropia caterpillar grows too large for its skin four times 
during its life, shedding each time, and the colors changing some- 
what with every cast. The last moult takes place when the larva is 
twenty-six days old. The body color is then a beautiful deep foliage 
green and the spines are varied in orange, yellow, and the brightest 
imaginable blue. For eleven days after this cast the giant caterpillar 
goes on feeding as before, finally reaching a length of nearly five 
inches before starting to spin its cocoon. Indeed at this period of 
its life, it is hard to imagine that this great green worm could be 
connected in any possible manner with the tiny, black-spined larva 
of thirty-seven days before. 

Although defenceless, the cecropia's protection is complete. Its 



THE CECROPIA MOTH 145 

green coloring mimics its surroundings closely. It is all but invisible 
at a distance, even to the human eye. To a bird, it is probably en- 
tirely so. When a bird comes upon one of these caterpillars at close 
range, it knows only too well that it is on dangerous ground, for the 
gaudy color of cecropia's spines actually serve to inform it that the 
creature contains poisonous ingredients and is not fit to eat. 

When the larva is ready for its cocoon, it crawls to some convenient 
spot in a corner, or under a piece of old lumber, usually in a more 
or less protected position, but never so that the moth would be ham- 
pered when hatching. When it reaches its final destination, from 
which the cocoon is to be spun, the larva becomes absolutely motion- 
less, remaining so for many hours. This condition probably has 
something to do with the formation of the silk in the creature's glands. 
No doubt it is necessary for a certain period to elapse before the 
silk will flow freely enough to be spun into a cocoon. 

When this period is over, the larva will suddenly be seen to stretch 
its head out as far as it can reach, then touching the object with 
which it comes in contact, it fastens the pure silvery silk to it. Now 
the insect turns its entire body with the exception of its last segment. 
Then, throwing its head back over the body, it pulls a thin silken 
thread from its mouth, fastening it again to the farthest point that 
can be reached at the back. This operation is repeated hundreds of 
times, in every direction, until at length the larva has completely cov- 
ered itself. A second cocoon, much smaller than the first and more 
compactly constructed, is then spun within the first. The silk leaves 
the insect's mouth in a silvery liguid, hardening only when it comes 
in contact with the air. This turns to a deep reddish-brown about 
five days after the cocoon has been completed. 

Inside the cocoon, the larva shrinks to about one-third its normal 
size. Then the skin begins to dry and becomes very brittle, finally 
splitting down the back and thus changing the larva to a pupa, or 



146 INSECT BEHAVIOR 

chrysalis, as this stage is commonly called. On the surface of the 
pupa, the wings and feelers, legs and eyes of the future moth are 
plainly visible through its reddish skin. In this form, the cecropia 
lies dormant for thirty-nine weeks in its silken tomb. 

Then comes a day when the hot sun of summer strikes the cocoon. 
Within, the pupal skin splits open and the silk of the cocoon parts 
at one end. Its creator has excreted a few drops of fluid which dis- 
solve the strands and thus liberate the insect. A glorious deep red 
and grey moth with feathery feelers and great clear eyes pushes 
itself to the light of day. Then, clinging to the edge of its weather- 
worn cocoon, this wonderful insect creation prepares itself for the 
world. 

It stretches and expands its wings; waves them gently to and fro 
in the welcome sun, until the moisture of birth has disappeared. 
Then it rests for a time until the sun sets, a great glowing ball of 
crimson. When night falls over the land and the fireflies are once 
more upon the wing, the moth answers the strange mating call 
within. It flies away through the perfumed , foliage of the first 
sultry night of summer. 



kii 



li 





n i_i -^ 




CHAPTER XIX 

nature's way with undesirables 

WEIRD and imperative upon the hazy early morning 
air floats the ephemeral perfume of the blooming 
squash plants. Yonder in the garden a long narrow 
line of them stretches out, from one end of the dew- 
drenched field to the other, their great yellow blossoms standing out 
in bold relief against the deep, rich green of their foliage. Weak 
indeed is that weird fragrance, from a human point of view, yet it is 
strong enough to bring the flower's insect admirers, the beetle and 
the bee, from far and near to their gaping yellow throats. 

Simple enough to be sure, and as commonplace as any other cluster 
of color words, yet in that little paragraph about the squash, the 
beetle and bee, there lies a story, which is one of Nature's best. 

A black, shiny beetle darted through the air, first this way then 
that, a carefree fortunate creature indeed, too simple to understand 
such a thing as care or worry. Once or twice it circled above the 
garden greenery, its filmy wings glistening in the sunlight. Then 
suddenly, as though pulled by an invisible cord, it wheeled sharply 
and flew straight into the mouth of a gaping yellow blossom. The 
insect had felt the call of that oddly scented perfume and it had 
proved irresistible. 

Eagerly the beetle scrambled down the big yellow pistil to satisfy 
its thrust for the sweets which surely existed in the flower's hidden 
depths. But there was a rude surprise in store for him, for when 
he reached the bottom of the blossom the sweets were nowhere to 

be found. Search as the beetle might, there was nothing there, yet 

147 



148 INSECT BEHAVIOR 

there was the odor, powerful and appetizing, unmistakably from a 
delicious nectarine fluid. Baffled and undoubtedly angry at being 
thus fooled, the insect turned and retreated in panicky haste to the 
outer air and a world of things more friendly. 

Now, shortly after this incident, there came a honey-bee to the 
blossom, attracted by that same curious fragrance, or perhaps by; 
the brilliant yellow coloring of the flower's petals. Down the pistil 
went the bee, as eagerly as the beetle had done but a minute before, 
until it reached the bottom of the flower. Then it quivered its wings 
and body nervously, as though something were absent that should 
have been there, but soon it settled down, contented and motion- 
less, drinking in the delicious saccharine, from the flower's hidden 
storehouse. What a contrast to the excited clumsy beetle, who, just 
as Nature intended, would never taste those sweets or know the 
secret of their seclusion! 

But why this apparent favoritism of Nature for the bee? Why 
should not the beetle also sip the honey? It is not favoritism. Such 
a thing does not exist in Nature. It is simply her method of pro- 
tecting the flower from undesirable visitors and the beetle is one of 
these, as we shall presently see. But let us first study the flower for 
a minute, before going any further, that we may understand more 
clearly. 

Plants are helpless inhabitants of our world, destined to spring 
from a seed and to spend their life just where that seed chanced to 
be dropped. But like most other living things, they must be fertilized 
before they may produce new seed that will grow and perpetuate 
their race. Their pollens must cross or intermingle, for that is the 
way plants are fertilized, yet they cannot move about, cannot come in 
contact, except by chance, so Nature is called upon to supply the 
means. 

She has supplied two ways for the plant world. One the wind, 





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Q, (LI 

a c 

^ (U 



O 



NATURE'S WAY WITH UNDESIRABLES 149 

which blows the pollen from one flower to the next, but the prin- 
cipal agents are insects and it is to the bee that the squash plant 
owes its existence. 

At the bottom of the pistil within the squash blossom there is a 
tiny opening slightly larger than a pin hole, the only entrance to 
the hidden honey-cup which lies below. 

Now, if we were to examine a honey-bee closely, it would be seen 
that the legs of the insect are broadly constructed and thickly clothed 
in a growth of powerful wiry hairs, while a short study of the mouth 
parts would reveal a strong triple tongue, long and very flexible. 

When the insect crawls down into the blossom, it does not rush 
madly about after the method of the beetle, for Nature has long 
since _taught the honey-bee the secret of finding the hidden nectar. 
It requires but a second or two to locate the tiny door through which 
it plunges its long tongue into the pure sweet honey. Meanwhile the 
insect's motions have shaken the pollen from its fastenings above. 
Down it comes in a yellow shower about the drinking bee. Some 
of it sifts in among the hairs upon the insect's thighs and here it 
clings until the next blossom is visited. Now some of it is bound to 
be brushed off each time the busy bee crawls within a blossom. Thus 
the pollens are blended and the flowers fertilized. In short, it is a 
fair exchange between two different kingdoms ; the bee makes possible 
the offspring of the plant and the plant gives the honey for the off- 
spring of the bee! 

And now let us turn to the poor beetle, who alas cannot partake 
of the flower's store of nectar, try as it might. Unlike the honey- 
bee the beetle's legs are hard and shiny and bear no fuzzy hairs to 
which the pollen might stick. He is useless to the flower and there- 
fore unwelcome. Yet were it not for Mother Nature, with her de- 
vices for protection, the beetle might drain the honey from the flower, 



I50 INSECT BEHAVIOR 

fly away without a speck of pollen clinging to its legs, and thus ac- 
complish nothing, save the downfall of the flower. 

But the beetle has a short tongue indeed, as compared with that 
of the bee, and plunge it as he might into the pin-hole entrance at 
the bottom of the pistil, it could never reach the sweets in the bottom 
of the cup. Thus is the squash protected from such insects which 
would not give their services in exchange. He leaves the flower no 
wiser than he came, and the honey lies unspoiled and untasted in 
its cup, to await the coming of the friendly bee. 

Of course there are certain insects, other than the many species 
of bees, who are so constructed by nature that they are able to obtain 
the squash flow^er's honey, but even these are beneficial in most cases. 
There are the Bombyliid flies, for instance, who resemble a bumble- 
bee so closely that one unfamiliar with them would think twice be- 
fore doing anything to arouse their possible displeasure! These in- 
sects possess a long flexible tongue like that of a bee, and although 
the hair is absent upon the legs, the body is so thickly clothed with 
it that it undoubtedly serves as an efficient carrier for pollen. 

Many tiny crawling creatures of the insect world, small enough 
to insert their entire head or body into the nectar cup, would be seri- 
ous factors for the plants to reckon with, had not Nature supplied 
them with numbers of stout hairs and spines of their own, over 
which the insects cannot pass. Nothing is overlooked. Nature is 
indeed a watchful mother. 

There are few of us who would care to walk abroad upon a sum- 
mer's morn down in the garden among the blooming squash, and 
see and watch these things until they knew the why and wherefore 
of it all. How many of Nature's secrets there are about us all the 
time, just like this little story of the squash, the beetle and the bee, 
only waiting for the one who cares enough to learn them. 




These are not flowers, but the foamy dwellings of immature spittle bugs 




Showing the growth of the spittle mass from founilation to the completed mass. Life size 



CHAPTER XX 

SPITTLE BUG SPITTLE 

THERE are few country people who have not at one time 
or another during the summer months, seen curious, foamy 
masses clinging to the stems of grass or leaves, and created 
by the spittle bugs/ Yet how few have ever taken the 
trouble to look into these odd creations of the insect world, and how 
much of interest they have missed through their lack of curiosity. 
Hidden beneath that foamy covering of tiny bubbles, lies an in- 
sect, insignificant to be sure, but as interesting in its daily life as 
the "Big Bugs" with which we are all familiar. Often these spittle 
masses occur by hundreds in our fields, but are overlooked because 
the insect knows enough to build its habitation where white clover 
blooms. In shape and color the foamy masses match the clover 
so perfectly that a casual observer does not notice the difference. 

The spittle bug is, of course, primarily hatched from a tiny egg 
which is probably placed by the parent somewhere about the base 
of a stem of grass. A single egg is usually deposited upon each 
stem, although at times one will find exceptions to this rule. Such 
cases are proved by the occasional presence of several insects in a 
single mass of spittle. However, little or nothing is really known 
concerning the egg stage of the spittle bug, the above statements 
being simply the writer's own conclusions, drawn after considerable 
study of these creatures. 

Our real intimacy with the spittle bug commences when, having 
left its egg-shell prison, it comes forth into the world in the form 

^ Cercopidae. 

151 



152 INSECT BEHAVIOR 

of a soft-bodied, buff-colored insect, whose general appearance re- 
minds one of a tiny submarine. 

When the eggs have given birth to their curious children, the 
insects climb some distance up the grass stems, and here one may 
observe the most interesting of their habits — the formation of the 
spittle mass which has earned for the insect its name. When about 
to begin house building, the insect ejects a tiny drop of extremely 
sticky liquid upon the grass stem, into this mass it inserts the tail 
end of its body, which is fitted with a specialized apparatus for 
blowing bubbles. The apparatus opens slowly, allowing some of 
the sticky fluid to flow across its concave surface. Now the orifice 
closes slowly, while a slight pressure from within causes a tiny 
bubble to be blown. This does not burst, on account of its sticky 
covering, and as the process continues, thousands of these tiny spheres 
of mucus are manufactured, which eventually surround and com- 
pletely cover the insect. The blowing apparatus in action reminds 
me of a gold fish's mouth, a continual opening and closing motion, 
but working, of course, to an entirely different end. 

Thus the spittle bug hides itself away, safe from the hungry jaws 
of its numerous enemies. 

It must be understood that when living in this curious dwelling 
the insect is not mature, but is in a form which corresponds to a 
caterpillar before it becomes a butterfly. Caterpillars feed upon 
the leaves and stems of various plants and trees, but just what com- 
poses the diet of the spittle bug is more or less a disputed question. 
This, and the reason for its manufacture of the sticky froth, are 
points which have been neglected by entomologists. 

It seems as though either one of these unsolved mysteries might 
explain the other. The froth is extremely sticky and therefore acts 
as a trap for many tiny insects. In the insect world we find a great 
many species which live upon animal food when young, so why 




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SPITTLE BUG SPITTLE 153 

should not the spittle bug be one of these, feeding upon the victims 
which it catches in its snare? In more than one instance, the writer 
has found a spittle bug in the center of its lair, clinging tightly to 
the body of some unfortunate insect. 

In a large mass of spittle, one will occasionally find several of 
the insects living together in various stages of development. This, 
however, is unusual and in the great majority of cases but a single 
insect inhabits each mass. 

Several days after leaving the egg, the insect stops feeding and 
remains motionless within its dwelling of bubbles for two or three 
days. At this period the spittle commences to dry up, leaving a 
cell about the spittle bug's body in which it undergoes the trans- 
formation to a perfect insect. Its old skin splits apart and slowly 
the mature creature pushes forth. She is a slender winged insect, 
longer and more agile than the form from which she has just risen. 
After brushing and drying herself she burrows through the dried 
white mass and soon becomes the mother of a new generation. 

There are spittle bugs of many sizes, shapes, and hues, but this 
brief life history will suffice for most of them. Where they differ 
chiefly, is in the plant upon which they occur. Some blow their 
houses among the grass, others upon the leaf stems of basswood, and 
giant ones occur upon the needles of the long-leaved pines. 

Wherever one goes in summer, providing there be vegetation, 
one finds these strange little creatures decorating the foliage with 
their sticky shelters of foam. 



CHAPTER XXI 

THE LIFE OF THE THREAD-LEGGED BUG 

Ernes a longipes 

IT IS a musical night in mid-September, the zenith of the insect 
season. Far in the void, moist bands of mist pass slowly across 
the moon, raising and lowering the pale glow in the world 
about us, first obliterating, now bringing into clearer relief, 
shadows that melt away almost as we discover them. Dew is heavy 
on the grass tips. It sparkles in the silver light and adds its mite to 
September's fragrance, for each month has its perfume. 

Out there in the moonlit meadows and woodland, insect events 
rush on. Peace and war and industry are heralded, each sound, 
however tiny, fraught with meaning. All are working to one end. 
This droning insect music of summer is the battle cry of their race, 
each individual singing that he shall survive to perpetuate it. 

By some the battle is lost, but over each loser a victor shouts 
his triumph and so the race goes on. Everywhere tiny wings vi- 
brate with songs of life, while delicate odors emanate from quiver- 
ing bodies, that strange mates may travel through the labyrinth 
of life, at length to meet successfully! At our very doorstep lies 
this world of insects, yet how little we understand and know its in- 
habitants. 

Now on this very September night, perhaps the strangest of all 
these myriad insects is preparing to perpetuate her race. She is 
one that lays no claim to fame, for man has neglected her family 

history most completely. Unlike the housefly or mosquito, she is 

154 



THE LIFE OF THE THREAD-LEGGED BUG 155 

of little account in our daily afifairs, so the facts of her curious 
home life have never been chronicled. 

Mating over, and perhaps feeling the paralysis of age creeping 
over her, tonight she hastens to her duty. 

Among the weathered rafters of a shed, or perhaps an abandoned 
house, she deposits her tough black eggs. They are cigar-shaped 
with a slight flaring lip at one end and deeply fluted like a Corin- 
thian column. One by one they are attached to the roughened 
surface of the wood. Sometimes but an hour, at others an entire 
day elapses between the laying of each, thus they rarely appear in 
clusters. Wherever the parent wanders from day to day, the eggs 
will be found, one by one in her path. 

From early September until late October, the process goes on, 
until the first frosts of winter claim the declining creature, leaving 
only the dormant eggs as evidence of the parent's existence. 

She is a grotesque object at best, this mother, slow and deliberate, 
with limbs as delicate as threads and a body scarcely more robust. 
Yet with all her physical shortcomings, she is a personality in her 
world. 

She has left the common horde of insects and taken up her abode 
with man. Once, with other arboreal creatures of the clan she 
lived and died among the foliage, but now she finds human habita- 
tions to her advantage. Doubtless, in ages past, she was a dominant 
predacious insect of the air, a hawk in her world, dreaded by 
others less spry. Now, in her new habitat, after years of disuse, her 
wings are narrow and degenerate, scarcely capable of easing her fall 
when dropped from one's hand. Wings have ceased to be a ne- 
cessity, but other characters, unknown perhaps in other generations, 
have been acquired. Her legs have grown to immense length with 
a tiny diameter of corresponding absurdity. The front pair have 
shortened and developed into spiked and jointed forceps, while the 



156 INSECT BEHAVIOR 

tips of the other four have become cleft like a cow's, all as we shall 
see for a purpose. 

The thread-legged bug is extremely sluggish, every move being 
made very slowly and with great deliberation. Indeed they would 
make little progress in a lifetime, were it not for their habit of 
never resting. They are as active by night as by day and sleep is 
unknown. 

In length the creature's body measures an inch and a half, 
while in width it is comparable to a sliver cut from a match. Two 
of the three pairs of legs are long and slender and the third pair, 
nearest the head, resemble a pair of arms bent abruptly at the 
elbows with hands bent backward towards the wrists. Upon these 
powerful tongs are rows of stiff hairs interspersed with an occa- 
sional sharp spike, which serve as meat hooks for the insect's vic- 
tims. 

The head is very minute, supplied with red, highly compounded 
eyes, which protrude in a ridiculous fashion, and a long bayonet 
which is hollow and used for sucking the juices from the creature's 
luckless victims. 

Strange to say, flies and small bees form the thread-leg's chief 
article of diet. One wonders, in view of the insect's sluggish nature, 
how such agile objects can be captured. The original method, em- 
ployed by the thread-legs of the past and those few who still cling 
to the ancestral home among the foliage, was doubtless to remain 
motionless, like the assassin bugs, where flies and bees abound. 
Drunk with the liquor of newly opened blossoms, they were easily 
fallen upon and devoured. 

But what of food in the creature's new home, among the weathered 
timbers of its man-made dwellings? It is there to be sure, flies, and 
even tiny bees, searching for tunnels wherein to rear their progeny. 
In quality and quantity the supply is all that can be desired, but how 




A stampede of thread-legged bugs, racing slowly tlirougli a spider's web towards an enraiiglod victim. Twice 

life size 




Greatly enlarged head of the thread-legged bug showing sucking apparatus. The two threads protruding from 

the creature's nose are its feelers or antennae 




A'cha.acre,istic nttirude of the thrcad-Ie.gccj bug .^,on at rest i.wlth head down and Cone le.s or ron.s .crctchcJ 

straight out in front. Twice life size crctuua 




A thread-legged bug casting its skin just before becoming mature. Hanging head down the insect draws Itself 
A thread leggea Dug c^ ^^^g^^^ ,„^ering. Note the eye, and degenerate wmgs. Enlarged twice 



THE LIFE OF THE THREAD-LEGGED BUG 157 

to capture it? To us the problem would appear difficult. Not so to 
the insect. 

Among the old beams and timbers, spiders have built their webs 
for generations. They have lived and died and abandoned their 
silken snares to whatever purpose they might serve. At first they 
grew heavy, grey with the dust of disuse. They served no second 
purpose and eventually collapsed. 

That was long in the pastj^ long before the thread-leg, abandoning 
its home in the foliage for an easier mode of existence, crept into 
the shelters of man. 

Perhaps that first man-shelter, reached by the thread-leg, was as 
primitive as the insect herself, yet here she doubtless experienced a 
cobweb for the first time and found it to her advantage. Perhaps 
there was a fly entangled in the snare and no doubt she was hungry. 
Next day, another creature, entangled, kept her in the neighborhood 
of the abandoned web. Day after day her meals appeared, unbidden 
by nectar. As if by magic, she had simply to step forward and claim 
her prey. 

She found herself peculiarly adapted to living in the web. Her 
long legs with cloven claws made travel easy, while deliberate, slug- 
gish motions minimized the danger of entrapping herself. 

Here at length, she was sought by the male. Here she mated, spent 
her reclining days and eventually died, leaving in her dormant eggs 
the seeds of a new habit, sleeping now, but one day to affect her entire 
race! 

It is strange that the thread-legged bugs should abandon the world 
of sunlight and blossoms for their dingy abode among the spider 
webs, yet it is in keeping with their slow and indolent mode of life. 
Perhaps it is better to have one's food brought magically to hand 
than to work for it, even at the sacrifice of sunlight 1 



158 INSECT BEHAVIOR 

The eggs winter over in a dormant state, hatching sometime during 
the spring. A quantity carried to South America for experimental 
purposes poured forth their quaint inmates in the latter part of 
February, but in the North, May is doubtless the hatching month. 

The young thread-legs are exactly like the parents, only quite 
transparent and scarcely over a quarter of an inch in length. They 
grow quite rapidly, casting ofif their old skin, like a caterpillar, sev- 
eral times before they become full grown, in August. At this time, 
shortly before paring commences, I have witnessed what I called 
"Stampedes." The insects congregate in hundreds about certain 
webs, which seem to be more popular than others. All goes well 
for a time, the individuals fraternizing with one another peacefully 
enough until some unfortunate creature from the outer world chances 
to drop into this snare. 

The instant a victim becomes entangled, a most ridiculous stampede 
follows to see who will first reach and bear off the juicy morsel. 
The absurdity of this event is increased by the fact that the would- 
be stampeders cannot possibly move rapidly. The sight reminds me 
of that nightmare wherein I am in dire need of running, yet try as I 
may, I can move no faster than a snail. 

When feeding, the creature holds its prey in the bend of its spiked 
forelegs at a safe distance from its head and body. Its sharp sucking 
tube is then thrust into the captive, whose life is rapidly drawn into 
the body of the thread-leg. 

Flies, bugs and even bees hold no terror for this insect, who is 
immune from their bites and stings. From their position in the 
creature's outstretched arms they can reach no vital spots. A wildly 
darting sting, a poisoned fang or a tireless set of muscles are of no 
avail, and the thread-leg feeds at leisure. 

Thus these strange creatures live their easy, toilless lives. They 



THE LIFE OF THE THREAD-LEGGED BUG 159 

have no enemies that I can discover, no work, no worries, and they 
require no sleep. From the hour of birth to the hour of death they 
idle away their time. Eating is their sole occupation, yet they re- 
main one of the leanest creatures on earth! 



CHAPTER XXII 

TRAILING A BEE TO ITS LAIR 

A TINY solitary bee,^ with a yellow speck on each of her 
hind legs, winged her way to the sandy driveway, then 
after hovering for a second or two above a little hill of sand 
and pebbles, she dove straight as an arrow, into the hole in 
the center of the mound. 

Near by there was another creature, a huge two-legged one, thou- 
sands of times the size of the bee, but that little insect excited the 
big animal greatly, so much so in fact, that he could not rest until 
he had seen the inside of the little creature's nest and found out the 
why and wherefore of her each and every fiercely energetic move. 

But there was only difficulty and disappointment in store for the 
big creature, for in his haste to get at the secret, he tried to dig 
out the bee's home in the underworld and after following its curious 
winding course for a few inches, the sand and pebbles rolled into 
the opening, buried the unsuspecting insect and ended the matter, 
as far as that particular bee and her nest were concerned! 

Some days later, however, another little mound much like the 
first one, only higher, appeared upon the drive close to the old site. 
Now it happened that the big interested creature also spied this 
second little heap of sand and stones. The sight made him rejoice, 
but he resolved to be more cautious, lest he destroy another home 
before finding out the mysteries going on within. 

All that day and all of the next that little bee was watched, and 

each time that she came to the nest, her thighs were clustered with 

^ Colletes. 

i6o 




^ . 4. - 




•AS^^tl 



12::^ 






The tiny solitary bee resting between polen-laden 
journeys. Life size 



Making a plaster cast of the bee's burrow 




Entrance to the bee's tunnel showing general surroundings. Somewhat reduced 



TRAILING A BEE TO ITS LAIR i6i 

yellow dust and each time she left the mound, that yellow dust 
was gone. 

Here then was the first mystery, one which might be cleared be- 
fore the nest was even touched, and one which was sure to prove 
interesting. When the little insect returned, for perhaps the fiftieth 
time that day, she was rudely surprised to find herself fast in the 
folds of a net which would not yield, instead of in the darkness of 
her tunnel. But she was not to be injured. Her only loss were 
those two yellow masses upon her legs and then she was free once 
more. 

The yellow masses proved to be pollen, the seed germs of flowers, 
that yellow powder which one is sometimes dusted with upon brush- 
ing against a blossom. Even more interesting was the fact that the 
pollen was that of the goldenrod, and no goldenrod could be found 
within a quarter of a mile of the nest! Thus each time the insect 
returned with her burden of yellow dust, she had traveled half a 
mile. 

But why does she take that pollen from the light of day and carry 
it far below the ground, leave it and then hurry off in search of 
more? Let us follow her into the nest and see. 

When the little bee leaves the sunlight she does not go straight 
down, but follows a curious twisting tunnel, pitch black, and just 
large enough to fit her body. Maybe she would rather have 
it straight, but there are projecting roots, stones and many other ob- 
jects too large for her to move, and even a bee cannot foresee these 
obstacles. She must, therefore, dig around them, hence the shape 
of the burrow, which is seldom twice the same. 

At the end of this subterranean passage is an earthen cell, elon- 
gated and slightly larger in diameter than the rest. On reaching 
this little storehouse, for such it is, she removes the pollen from 
her thighs by means of her other four lees. Then she mixes the 



i62 INSECT BEHAVIOR 

yellow substance with clear sweet nectar, kneads it into a honey- 
paste and tamps it down upon the previous layers within the cell. 

What energy that little creature has to first dig that burrow, sixty 
times her own length, into the solid ground, then to fill the cell with 
pollen, which means hundreds of loads to be carried, kneaded and 
tamped into place. And even now she is not through, for there are 
eggs to be laid and perhaps other nests to be made and looked out 
for. 

The egg is laid upon the honey-paste within the cell and after this 
the mother is through with that particular nest, for it is now sealed 
and deserted. Within, the young bee, a white legless creature, 
hatches and feasts upon the generous store of sweetened pollen which 
the mother has supplied. How long it feeds, someone else must say, 
but soon it transforms into a chrysalis, lies motionless for some weeks, 
perhaps months, then pushes its way through the earth to the world 
of sunlight, a perfect insect. 

If it be a male, it mates and lives a life of ease, if a female, it has 
work to do, hard work and plenty of it, before an enemy or Jack 
Frost puts an end to its brief existence in our world. 

How did the man find out all this? By watching, constantly and 
patiently, not by guessing. Nor was it tedious, uninteresting work; 
far from it, the big two-legged creature was sorry when the work 
was finished and the little bee had flown to pastures new. 

But how did he know what that tiny subterranean passage was like, 
why did not the sand and pebbles fall into this one when it came time 
to explore its depths? New methods were used and caution 
triumphed, that is why. 

When the bee had finished her work about the nest, she was not 
allowed to seal it. Instead it was filled with liquid plaster of paris, 
which ran down inside, filling every little nook and corner of the 
tunnel. Several hours later it had hardened like rock, and the man, 



k^'^-'f' "-■ 




Model of the bee's nest made from a plaster cast. One-third natural size 







■^^^ii^w«* 






Interior of the bee's burrow showing cell hlled with honey paste. From the model. Twice life size 







Excavating the plaster cast of the burrow. Photograph one-third natural size 



TRAILING A BEE TO ITS LAIR 163 

with boyish enthusiasm and excitement, sat down upon the ground 
and very carefully chiseled the earth away. Every minute revealed, 
a new. twist or turn and every minute the excitement grew, as with 
an excavator of Pompeii, until the end was reached and the pollen 
found. 

Then the perfect cast was laid upon a smooth pine board and its 
course traced upon the wood in pencil. With the aid of a gouge and 
a sharp knife, a duplicate of the original nest was modeled in the 
wood, showing every turn and every indentation just as the insect 
had made them. Then the board was brushed with glue and 
sprinkled with fine sifted sand, taken from the spot where the nest 
actually existed. To represent the pollen, a touch of powdered yel- 
low felt was glued within the artificial cell, and it was finished a 
perfect model of the little creature's home. 

Then it was photographed as an everlasting monument to the skill 
and energy of the tiny insect who designed it. 



CHAPTER XXIII 

CAMOUFLAGED INSECTS 

BY Nature the art of camouflage has long been prac- 
ticed. It is her way of affording protection to those of her 
defenceless children who might otherwise fall victims to 
predacious enemies. To us the word is a war-baby, com- 
ing from the battlefields of France. It has since been applied to 
an endless variety of things; most anything, which by nature of 
peculiarly applied patterns, is made to blend with its surroundings, 
and thus appear more or less obscure to the eye. 

Among insects camouflage has been carried beyond mere arrange- 
ment of color pattern. We find creatures whose general outline as 
well as pigmentation mimics their natural surroundings to such a 
marked degree that it is often difKcult to distinguish where habitat 
leaves off and where inhabiter begins. 

This curious state of affairs has been developed through thousands 
of years by the process of selection. Individuals vary greatly in color 
and those fortunate ones matching their surroundings more closely, 
naturally survived longer than their less protectively patterned 
brothers. Thus, as time went on, the pattern of these selected in- 
dividuals became dominant of the species, developed in some cases 
to a phenomenal degree. 

A remarkable case of this kind is shown in Figure 109, of a cater- 
pillar or larva which later transforms into a geometrid moth. In 
the larval state the insect bears a very close resemblance to a twig. 
Its habit of clinging to a real twig with its posterior "legs" and 

allowing the body to swing out, adds to the illusion. The head of 

164 




Caterpillar of a geometrid moth which resembles the twigs of the insect's food plant, thus gaining immunity 

from the attacks of its enemies. Twice life size 




This remarkable caterpillar resembles the excretia of a bird so closely that only one accustomed to seeing it under 
all conditions, realizes that it is a living creature. Greatly enlarged 



CAMOUFLAGED INSECTS 165 

the caterpillar resembles a leaf bud, while in color the entire creature 
is an exact counterpart of a rough apple twig, the plant upon which' 
it naturally feeds. Thus complete immunity is secured from the at- 
tacks of birds and all enemies which depend chiefly upon sight. 

A similar case is that of the slug caterpillar, Figure no, of the 
family Cochlidiidae. Its general color is leaf-green with some small 
amount of dark red near the head, which is pointing downward in 
the photograph. On the whole, to the casual observer, it is scarcely 
distinguishable from a swollen bud. Even more remarkable are the 
caterpillars which rely for their protection upon their mimicry of 
the excreta of birds, Figure in. I have been completely fooled by 
these larvae on more than one occasion. They frequently rest in the 
center of a green leaf and while conspicuous, never suggest a living 
insect to the uninitiated. In color, the upper and lower portions of 
the body are dark chocolate brown, banded through the center with 
pure white, which suggests the lime so often seen in the excreta of 
birds. The entire creature is highly glossed, which gives a fresh 
and moist appearance to the object, which makes no attempt to con- 
ceal itself, depending entirely upon its strangely camouflaged body 
for protection! 

In the course of my field activities, I have run across a great num- 
ber of cases where insects were curiously camouflaged to their sur- 
roundings. They are far too numerous to describe here in detail, 
but one or two are of particular interest. 

In British Guiana, inhabiting the trails through the virgin forest, 
is a tiny species of thecla, a bright blue, angular-winged butterfly. 
Upon endeavoring to capture one or two specimens, I swooped with 
my net in the ordinary way, where several individuals were flying 
about chasing one another, but as I did so all of them disappeared 
as if by magic. In a few minutes they returned, one by one, appar- 
ently from the vegetation directly before my eyes. A second and 



i66 INSECT BEHAVIOR 

third swing of my net produced the same results. Try as I might, 
between swoops, I could find no trace of my quarry until they re- 
turned to the trail of their own accord, yet they never appeared to 
go far away. 

At length I decided to beat the surrounding vegetation, and upon 
doing so caught two of the butterflies. Examination revealed that 
the under side of the wings were bright green, which matched per- 
fectly with the jungle leaves. I stunned one and placed it upon a 
leafy twig and turned away. In a minute I looked back and found 
the insect with great difficulty, so perfectly did it blend with its sur- 
roundings. When I swung my net, the insects had retreated to the 
foliage and although bright blue in flight, they instantly disappeared 
upon folding their wings when coming to rest among the leaves. 

In the Andean jungle of Colombia, one finds strange transparent 
butterflies. Unlike our familiar species, they possess no scales and 
are therefore without color patterns. The wings are the color of 
clouded glass, but quite transparent. In flight they are easily seen, 
but upon coming to rest among the brown leaves which cover the 
forest floor, they become more or less invisible and are thus pro- 
tected. 

Placed upon a printed page, one may read through their wings as. 
readily as through a piece of glass, only the body and veins of the 
insect being too dense for this purpose. 

I once found a drinking place of these butterflies in Colombia. A 
huge moss-grown boulder, upon which a tiny stream of water con- 
tinually fell, produced a popular saloon to which hundreds of these 
skeleton insects resorted. It was an interesting sight to see them 
gathered together in such numbers to the exclusion of other species. 
From a distance only their brown bodies and wing veins were visi- 
ble, resembling a multitude of stick insects, clustered upon the water- 
soaked moss. 



CAMOUFLAGED INSECTS - 167 

In a great many cases insects are not camouflaged as we understand 
the word. Many are bright and gaudy and attract rather than de- 
ceive the eye. In such cases, these bright spots, bands, spines and 
ground colors serve as warning signals to the enemies of the insects. 
They are protective measures of another variety employed by Nature 
for a double purpose. They are to protect the bearer against its 
enemies and at the same time the would-be sampler of insects in 
general. 

Bright and gaudy colors are often a sign of poisonous qualities in 
an insect, or one whose blood lymph or other body fluids possess a 
disagreeable taste. In the light of the above statement it is inter- 
esting that many harmless and edible insects mimic in pattern those 
species who are really ill tasting or poisonous. Thus the great 
monarch butterfly is closely mimicked in color by another species. 

The monarch (Anosia plexippus) is one of the most successful of 
insects. It is abundant and widely distributed, due in all probability 
to qualities that make it distasteful to birds and other enemies, in all 
stages of its life. Thus it has become a dominant species in the insect 
world. 

To mimic such a species would be at once advantageous to other 
insects and, strangely enough, the viceroy butterfly (Basilarchia 
archippus) gains immunity from attack in this way, even though it 
is in all probability an edible species. 

In South America I found a species of Heliconidae, a medium- 
sized glossy black butterfly bearing rose-colored bands across the 
wings. This species, except in the contour of its wings, was closely 
mimicked by a species of Papilionidae, inhabiting the same general 
locality. The former are supposed to be inedible or distasteful. 
Endless cases might be cited, like the above, especially among 
tropical insects, who are camouflaged, so to speak, to resemble some- 



i68 INSECT BEHAVIOR 

thing which is dangerous and to be left alone by birds, lizards and 
other enemies of the insects. 

There is still another type of camouflage among insects worthy of 
mention, one which is doubtless effective in protecting absolutely 
harmless and passive creatures from being attacked and eaten. 

We find, for instance, the chrysalis of a butterfly, a species of 
Vanessa. It hangs by a tiny silk-fastened stem under a protecting 
fence rail. Within the shell of the chrysalis, there is nothing but a 
mass of disintegrating tissues, a thick fluid, studded with globules of 
fat. It is neither caterpillar nor butterfly. It cannot thrash about 
from side to side or make a demonstration, there are no spines to 
pierce a would-be enemy, no wings by which the creature might 
take flight. It is as helpless now as so much custard, for the insect 
is in the process of change from one form to another. 

Such is the actual condition of the pupal butterfly, but let us 
examine its outer covering. It is a frightful-looking objek:t, 
armored, and covered with sharp spikes between which beady false 
eyes peer out. It is absolutely harmless but appears otherwise. To 
birds it is doubtless a thing to beware of, yet one tiny puncture of its 
brittle covering would reveal a delicious feast within! 

Many insects are thus protected, ones that could not compete in 
any form of battle. They are given immunity from attack because 
they could not ward it off themselves. In the case of the trans- 
forming pupa, some such form of protection becomes a necessity. A 
butterfly in the making is as helpless as the egg from which it sprung, 
so Nature resorts to camouflage to terrorize the destroyers of her 
children. 




o 







V3 U 

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O 3 

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CHAPTER XXIV 

LIVING EXAMPLES OF THE GEOLOGICAL PAST 

STRANGE as it may seem, the most ancient types of insects 
are still represented alive, in the world today. Unlike the 
ancient men and mammals of our planet, whose scanty his- 
tory comes to us through occasional beds of, fossil remains, 
insects provide us, through those which live today, with an actual 
glimpse into the great geological past. 

Some of the creatures have underggne little change during 
millions of years. They are today almost what their ancestors were 
in those past ages, ancestors who roamed the. prehistoric fields and 
forests, now buried deep in the crust of the earth. 

That these insects still exist, almost unchanged, still primitive in 
their structure, shows that Nature does not always do away with her 
early experiments. She does not cause them all to become extinct 
in favor of more modern ones. 

These primitive insects which still inhabit the world, are known 
scientifically as Aptera, an order which includes two suborders, the 
Thysanura and CoUembola, commonly known as Bristle-tails and 
Spring-tails. 

Aptera today are the most widely distributed of all insects. They 
are found in Europe, the Faroe Islands, Chile, Alaska, Joseph 
Land, the Sandwich Islands, the South Orkneys, Graham Land, the 
United States, and South Victoria Land. Some have been collected 
from the snows of frozen mountain tops while others are found at 
sea-level, or below, in caves and caverns in the hottest climates. 

They are very delicate, often minute, soft-bodied insects, covered 

169 



I70 INSECT BEHAVIOR 

in some cases with microscopic lavender scales like those of a fish. 
Those belonging to the Thysanura possess strange forked appendages 
which protrude like long tails from the posterior segments of the 
body. These are in addition to the legs, and antennae or feelers, and 
their purpose is not definitely known. 

In Collembola the species are supplied with a catch, and spring, 
which upon release, hurls the creature bodily and automatically out 
of harm's way. They are also supplied with paired sacs, which are 
carried upon the ventral tube of the first of the six body segments. 
These assist the creature when walking upon very smooth surfaces 
and doubtless serve as breathing organs in addition. 

As it is extremely unlikely that such delicate insects could be 
transported across seas and oceans, their remarkable geographical 
range, so wide and discontinuous, suggests their great antiquity. 
Doubtless in ages past, before our planet was in the process of change 
towards what it is today, there were no seas or channels separating 
the various countries included in the range of the Aptera. The 
United States and Europe, together with Chile and the more 
isolated islands, were probably one continuous continent. If not," 
why then should we find these identical little insects in each of those 
places today? That they are of very ancient origin is undoubted. 
It is what makes the Aptera so important and interesting to scientists 
today. 

Geologists have found many fossil remains of these insects in very 
ancient strata of the earth's crust. A supposed specimen was 
unearthed from the Silurian deposits of New Brunswick, buried 
jhere during a comparatively quiescent period in the earth's history. 
At this time a great sinking of the land was followed by a relative 
rising, which affected wide areas in the northern hemisphere. Other 
remains found in Carboniferous deposits in France were of Aptera 
which lived in prehistoric forests of great exuberance, before they 




Once, with other arboreal creatures of the clan, the thread-legged bug lived and died among the foliage. Twice 

life size 




Poison spines on the lo caterpillar 

This catterpillar, whicli later transforms mto the lo moth, is splendidly protected from its enemies by masses of 

spines, each bearing a iiighly poisoned tip. The slightest scratch from one of these darts causes extreme pain, 

Itching and great discomiort probably due to formic acid, a substatue which serves as a protection to 

many insects 



EXAMPLES OF THE GEOLOGICAL PAST 171 

were buried to become our coal seams of commerce. Here and there 
a few others have been found in older strata but it is not until the 
Tertiary that their remains were found in any quantity. 

During this period or era, the configuration of the earth was 
steadily approaching that of the present day, but there still existed 
a great equatorial ocean, while East India and Africa, Australia and 
Asia, North Europe and America were probably united by land con- 
nections. The faunas of the planet also approached their present 
state, and might have continued to expand more broadly, had it not 
been for a rapid lowering of the earth's temperature, which brought 
about a great glacial period. 

Spring-tails of the present day live in moss, under logs or fallen 
leaves, in grass, on water, snow, or in almost any place that is suf- 
ficiently damp. Their mouth parts are hidden and very difficult to 
study, but the insects are doubtless vegetable feeders like their 
Bristle-tail relatives. 

Millions of years ago the latter probably fed on water-soaked seeds 
or other vegetable matter of a starchy nature, but today they inhabit 
the houses of man, feeding upon the paste which keeps our wall 
papers in place, or upon the same substance, when it may be found, 
in the bindings of books upon our shelves. It is a strange habit in- 
deed, to acquire upon one's Nth millionth birthday as a race! 

Another creature, still existing, whose kind may be traced like the 
Aptera, far into the geological past, is the inappropriately named 
wood-louse. In reality a terrestrial crustacean closely related to 
the land crabs and not an insect in any sense of the word, this little 
oniscus is familiar to everyone living in the country who has ever 
turned over a stone or log or a bit of decaying wood. 

Members of the Isopoda are represented in all seas and lands, the 
wood-louse being the only land-loving representative of the order. 



172 INSECT BEHAVIOR 

Hundreds of species are known in the world and they are perhaps 
one of the commonest creatures occurring in the United States. 

The female oniscus carries her eggs in a pouch which covers the 
under surface of her thorax. The young are exactly like the adults 
except for the last pair of legs, which are lacking, and these are not 
acquired until later in life. The significance of this strange fact 
would be hard to discover, and like the life histories of so many of 
our tiny creatures, lies shrouded in mystery. 

It is strange that these creatures and the Aptera, still progressing 
in our world today, have survived great upheavals of the earth, great 
changes of climate, great floods and glacial periods, and yet have 
come through unscathed to this modern century. Where great 
mammals, birds and reptiles of bygone ages failed and left us only 
fossil records of their existence, these tiny things succeeded and came, 
living into our day. They have been handed down to us by Nature 
as priceless heirlooms of our planet's ancient family. 



/- 




Wood lice or pill bugs. Though commonly termed bugs, they are in reality terrestrial crustaceans related to 

the land crabs. Four times life size 




A thysanuran or bristle-tail. A creature that has come down through the ages to eat the paste upon our wall 
papers and book bindings. One of the most primitive of existing insects. Enlarged three times 



INDEX 



Africa, 171 
Agalenidae, 104 
Agouti, 77 
Alaska, 169 
Andean jungle, 166 
Anosia plexippus, 167 
Ants, South American army, 118, 119, 120, 
122, 123, 124 

bite of army, 123 

Carpenter, no, in, 112, 115 
battles of, 114 

cattle tending, 113, 114 

Leaf-cutting, enemy of, 115, 116 
poison of, 116, 117 

Mound, experiment on, 134, 135 

Slave making, 112 

slave-making habit, reflex of, 112 
Ant battles, 114 
Ant birds, 124 
Ant cows, 113, 114 
Ant lion, 25, 105 

Ants, 109, no, in, 112, 113, 114, 115, n6, 
118, 119, 120, 121, 122, 123, 124, 134, 
Aphids, 113, 114, 134 
Aptera, 169 

distribution of, 169, 170 

fossils of, 170 
Archippus, Basilarchia, 167 
Asia, 171 
Asilidse, 128 
Attadae, 115 
Australia, 171 

B 

Bartica, 118 

Basilarchia archippus, 167 
Battles, ant, 114, 115 
Bee, bumble, 104 

blue-flower, 87 

green-flower, 87 

honey, 148 

humble, 87 
Bees, 87, 148, 104, 160 
Beetle, carabid, 147 

oil, J04, 105 

rove, 25 

Xenos, 97 
Beetles, 25, 97, 104, 105, 147 
Birds, ant, 124 
Black reed-wasp, 27 



121, 



"7, 
135 



Blue huntress, 68 

Blue mud-dauber, 138, 140 

Bristle-tails, 169 

British Guiana, 118, 165 

Bug, spittle, 151 

thread-legged, life history of, 154 
egg laying, 155 
food of, 156 
stampedes of, 158 
Bumble bee, parasite of, 104 
Butterflies, invisibility of, 165 

transparent, 166 

Heliconidae, 167 

mimicry of, 167 

monarch, 167 

mourning cloak, 168 
Papilionadae, 167 

thecla, 165 

viceroy, 167 



Caddice fly, 108 
Caddice worm, 107 
Caeruleum, Chalybion, 138 
Camouflaged insects, 164 
Camponotus pennsylvanicus, no, 115 
Cannibal wasps, 85 
Caterpillar, cabbage, 99 

cecropia, 114 

cochlidiid, 165 

protective colors of, 145 

slug, 165 

twig, 164 
Cecropia moth, life history of, 143 
Cecropia, Samia, 143 
Centipedes, 122 
Ceratinadae, 87 
Cercopidas, 151 
Chalybion caeruleum, 138 
Chile, 169 

Chlorion neotropicus, 68 
Cicada, 91, 92, 136 
Cinereohirtum, Trypoxylon, 27 
Cochlididae, 165 
Collembola, 169 
Colletes, 160 

burrow of, 161 

burrow, method of molding, 162 
Colombia, 166 
Controlled pupation, 77 
Crickets, sight of, 128 

tree, 125 



173 



174 



INDEX 



Crickets, 49, 50, 120, 128 
Crustaceans, terrestrial, 171 

D 

Daddy-long-legs, 120 
Deposits, carboniferous, 170 

tertiary, 171 
Dialyzer, insect, 65 
Dragonfly, 25 

sight of, 128 
Drassidae, 104 



East India, 171 

Emesa longipes, 154 

Epeiridae, 103 

Europe, 169 

Excretia, of young wasp, contents of, 38 

method of, 28, 57, 58 
Experiments, some insect, 134 
Exsectoides, Formica, 112, 134 



Faroe Islands, 169 
Filistata, 48 

Fistulare, Sceliphron, 60 
Fly, bombyliid, 150 

checker, 89 

flesh, 79 

greenbottle, 129 

method of feeding, 131 
benefit derived from, 133 

house, 79 

robber, 128 

trepetid, life history of, 78 
erergence of, 83 
pigmentation of pupa, 83, 84 
Flies, 78, 79, 83, 84, 89, 128, 129, 131, 133, 150 
Forest shell-wasp, the, 53 

life history and habits of, 54 
Formica sanguinea, 112 

exsectoides, 134 
France, 170 



Gasteracantha, 48 

Geological past, living examples of, 169 

Gibbosus, Philanthus, 85 

Gongylophosa, Rozites, 115 

Graham Land, 169 

Grasshoppers, 122 

Guiana, British, 118, 165 

H 

Hamatus, Zethusculus, 53 
Harvestman, 120 
Heliconidae, 167 
Histogenesis, 37, 38 
Histolysis, 37, 38 



Hornets, 98, 99 

How the greenbottle does its duty, 129 
Howling monkey, 77, 78 
Hydropsychidae, 107 



Insects and other strategists, 102 
Insect eye, anatomy of, 126 
Insects, as pollen carriers, 149 

camouflaged, 164 

protective patterns, how obtained, 164 

sight of, the, 125 

warning signals of, 167 
Insect world, at close range, the, 19 

geography, of, 24, 25 
Isopoda, 171 



Joseph Land, 169 
Jungle, Andean, 166 



K 



Kalacoon, 27 



Larval sacrifice, 33 

Leucotrichium, Trypoxylon, 40 

Living examples of the geological past, 169 

Longipes, Emesa, 154 

Lycosidae, 104 

M 

Meloidae, 104 
Micrathena, 48 
Milch cattle, 134 
Monkey, howling, 77, 78 
Mosquito, 79 
Moth, cecropia, 143 

geometrid, 164 
Myrmeleonidae, 105 

N 

Nature's way with undesirables, 147 
Neotropicus, Chlorion, 68 
New Brunswick, 170 



O 



Observations on ants, 109-124 
Oil beetle, 104, 105 
One-banded dauber, 60 
Original Paper makers, 95 
Osmosis, apparent of egg film, 65 



Pallipes, Polistes, 95, 101, 138 
Papilionidae, 167 



INDEX 



175 



Paralysis, artificial of spiders, 56 

meaning of, 51 
Paralyzed provender, 46, 52 
Pennsylvanicus, Camponotus, no, 115 
Phalangidea, 120 

Philanthus gibbosus, life history of, 85 
Plants, fertilization by insects, 148, 149 
Plexippus, Anosia, 167 
Podium rufipes, 33 
Polistes, pallipes, 95, loi, 138 
Polyergus rufescens, 112 
Pontius rapae, 99 
Provender, paralyzed, 46 
Pupation, process of, 35 

controlled, 77, 78, 79, 80, 81, 82, 83, 84 
Pustulata, Winthemia, 4, 89 



R 

Rapae, Pontius, 99 

Roaches, wood, 34, 122, 123 

anatomy of, 51 

nervous system of, 51 
Rozites gongylophosa, 115 
Rufescens, Polyergus, 112 
Rufipes, Podium, 33 



Sandwich Islands, 169 

Sanguinea, Formica, 112, 134 

Sarcophagidae, 129, 133 

Sceliphron fistulare, 60 

Sight of insects, 125 

Some insect experiments, 134 

South America, 118, 165, 166, 167, 169 

South Orkneys, 169 

South Victoria Land, 169 

Span-worms, 123 

Speciosus, Sphecius, 91, 136 

Sphecid's duty, the, 91 

Sphecius speciosus, 91, 136 

Spittle bug spittle, 151 

Spittle, how produced, 152 

Sphex, 62 

Spiders, drassid, 25, 104 

anatomy of, 47 

nervous system of, 47 

orb-building, 103 

platform-building, 103, 104 
Spilographa, 78 
Spring-tails, 169 



Tachina, red-tailed, 89 

Tachininae, 89 

Thecia butterflies, 165 

Thread-legged bug, the life of, 154 

Thysanura, 169 

Trailing a bee to its lair, 160 

Tree cricket, 125 



Trepetidae, 78 

Trypoxylon, cinereohirtum, 27 
leuAtrichium, 40 

U 
Undesirables, Nature's way with, 147 



Vanessa, 168 
Vermilion-nut, 77 



W 



Wasps, accuracy of in finding nests, 62, 63, 64 
ancestral form of, 36 
appendages, use of pupal, 75 
Black reed, life history and habits of, 27, 

28, 29, 30, 31, 32, 49 
Blue huntress, life history and habits of, 68, 

69> 70, 71. 72, 73. 74, 75, 76 
Blue mud-dauber, experiments on, 140, 141 
Cannibal, life history and habits of, 85, 86, 

87, 88, 89, 90 
cannibalistic instincts of, 87, 88 
characters, acquired pupal, 75 
digger, Great golden, 91 
egg film, osmosis of, 65 
food, substitution of young wasp's, 55 
Forest shell, life history and habits of, 53, 

54, 55, 56, 57, 58, 59 
Long black reed, 62 
One-banded dauber. Life History and habits 

of, 60, 61, 62, 63, 64, 65, 66, 67 
Paper, effect of cold on, loi 

experiments on, 138, 139 

food of young, 96 

method of paper making, 96, 97 

parasite of young, 97 

life history and habits of, 138, 139 
Prey, artificial paralysis of, 56 

capture of, 70 

stinging of, 47 
provisions, significance of choice of, 42 
Provender, preparation of, 47 

pupae, appearance of pigment in, 58 

cause of dull color of, 58 
Lumberess, 50, 51, 52 
Mason, 68 

Red-legged digger, 62 
Roach-killer, 33, 39, 49, 52 
sentinels of, 100 
Solitary, food of young, 55 

peaceful nature of, 91 
Sphecid, experiments on, 136, 137 

life history and habits of, 91, 92, 93, 94 

method of carrying pre}', 92, 93 

toilet of, 94 
squeaking, interpretation of, 28 
sting poisons, effects of, 47, 48 



176 



INDEX 



Wasps, varnish, 44, 46 

victims, forms of paralysis in, 48, 49 
White-footed, life history and habits of, 40, 
41, 42, 43, 44, 45, 46, 47, 48, 49 
sense of direction of, 62 
wings, unfolding of, 58, 59 
young, feeding stimulus of, 73, 74 
method of feeding, 72, 73 
starvation of, 67 
varnish of, 44, 66 
White-footed wasp, the, 40 
Wasps, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 
38, 39, 40, 41, 42, 43, 44, 45, 4^, 47, 48, 
49, 50, SI, 52, 53, 54, 55, 56, 57, 58, 59, 
60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 
71, 72, 73, 74, 75, 76, 85, 86, 87, 88, 89, 



90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 
loi, 136, 136, 138, 139, 140, 141 

Winthemia, 4-pustulata, 89 

Wood-louse, 171 

Worm, span, 123 



Xenos, beetle, 97 



Yellow jacket, care of young, 99 



Zethusculus, hamatus, 53 



LIBRARY OF CONGRESS 




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